the association between neuroticism and secondary uterine inertia1318418/... · 2019. 5. 27. · in...

Maria Lundström Medicine programme, 2017

1

The association between neuroticism

and secondary uterine inertia

By: Maria Lundström

Supervisor: Alkistis Skalkidou

Co-supervisors: Cathrine Axfors, Emma Bränn & Emma Fransson


2

Abbreviations BMI – Body mass index CS – Caesarean section E – Embitterment FFT – Five factor theory ICD – International Statistical Classification of Diseases and Related Health Problems LA – Lack of assertiveness LD – Labor dystocia M – Mistrust MBR – Medical Birth Register PsTA – Psychic trait anxiety SFOG – The Swedish Society of Obstetrics and Gynecology in Swedish ’Svensk Förening för Obstetrik och Gynekologi’ SPMs – Social personality models SPSS – A statistical program used for statistical analyses in this study. SS – Stress susceptibility SSP – Swedish universities scales of personality STA – Somatic trait anxiety


3

Abstract

Background: Neuroticism is a personality trait that causes greater reactivity to stressors and results

in a more frequent experience of negative emotions, like anxiety. Uterine inertia refers to prolonged

labor and can be caused by a number of known risk factors like high age or high body mass index;

having fear of childbirth could be a risk factor for prolonged labor as well. Secondary uterine inertia

is here defined as no progress in labor during 2 hours after an initial normal progress.

Aim: In this study we investigate the association between neuroticism and secondary uterine

inertia.

Method: This study uses data from the Swedish Medical Birth Register, including a total of 1864

women. The women’s grade of neuroticism was assessed with the Swedish universities Scales of

Personality. We compared the first and second quartile of the population on the scale of neuroticism

with the fourth quartile to see whether there were differences in the risk for secondary uterine

inertia.

Results: There were no association between neuroticism and secondary uterine inertia in our

material, showing secondary uterine inertia in 11,1% in both the high and low neuroticism group.

Conclusion: We could see no association between neuroticism and secondary uterine inertia and if

replicated even in other samples, results point to there not being a use for assessment of neuroticism

for the identification of individuals for high risk for uterine inertia.


4

Table of contents Populärvetenskaplig sammanfattning på svenska ................................................................................ 5

Background .......................................................................................................................................... 6

Personality ........................................................................................................................................ 6

Stability of personality ..................................................................................................................... 6

Neuroticism ...................................................................................................................................... 7

Neuroticism and health outcomes .................................................................................................... 7

Uterine inertia and secondary uterine inertia ................................................................................... 8

Neuroticism and childbirth .............................................................................................................. 9

Neuroticism and uterine inertia ...................................................................................................... 10

Aim .................................................................................................................................................... 11

Method ............................................................................................................................................... 12

Study sample .................................................................................................................................. 12

Swedish universities Scales of Personality .................................................................................... 12

Swedish Medical Birth Register .................................................................................................... 13

Statistical methods ......................................................................................................................... 13

Statistical analyses were performed with the statistical programme SPSS (version 25.0).

Independent T-test was used for parametric numeric data. Chi2-test was used for parametric

nominal data and for non-parametric data we used Mann Whitney-test. Futhermore, multivariable

logistic regression was used in order to adjust for possible confounders and/or mediators. ......... 13

Potential confounders and mediators ............................................................................................. 13

Results ................................................................................................................................................ 15

Discussion .......................................................................................................................................... 19

Main findings of the study ............................................................................................................. 19

Strengths and limitations ................................................................................................................ 20

Conclusions .................................................................................................................................... 22

Future research ............................................................................................................................... 22

Acknowledgements ............................................................................................................................ 24

References .......................................................................................................................................... 25

Appendices ......................................................................................................................................... 30

Appendix 1 – ICD codes ................................................................................................................ 30

Appendix 2 – SSP manual ............................................................................................................. 31


5

Populärvetenskaplig sammanfattning på svenska Värksvaghet är något kvinnor kan drabbas av under förlossning och innebär att den aktiva

förlossningen, då kvinnan försöker krysta ut barnet, pågår längre än förväntat eller att

livmodertappen, som barnet ska komma ut genom, öppnas långsammare än förväntat. Detta innebär

att livmodertappen öppnas mindre än 1 cm/timme. Ett utdraget förlopp innebär risker både för

kvinnan och barnet. Värksvaghet kan delas in i primär och sekundär värksvaghet, och i denna studie

fokuserar vi på den sekundära. Sekundär värksvaghet innebär att kvinnan först kommit in i den så

kallade aktiva förlossningen men att förloppet sedan stannar upp.

Neuroticism är ett personlighetsdrag som innebär ökad förekomst av upplevelse av negativa känslor

som ångest, rädsla och ilska i stressande situationer. Det är kopplat till lägre tro på att själv klara

utmanande situationer och förklaras med att personer med hög grad av neuroticism kan tänkas ha

överaktivitet i hjärnans stresscentrum, som är grunden för just dessa typer av känslor. Förlossning

kan ses som en utmanande situation.

I denna studie undersöktes om det fanns en koppling mellan neuroticism och värksvaghet. I studien

ingår totalt 1864 kvinnor. Vårt studiematerial kommer ifrån flera mindre studier där de

medverkande har svarat på ett formulär som kallas Swedish universities Scales of Personality, för

att skatta personens grad av neuroticism. Studierna har slagits ihop och man har sedan kopplat

informationen från dessa studier med information från medicinska födelseregistret om mammornas

ålder, BMI, diagnoser mm. I studien jämfördes de med låg och de med hög grad av neuroticism för

att se om de i olika utsträckning fått diagnosen sekundär värksvaghet.

Vi hittade ingen koppling mellan neurotisk personlighet och sekundär värksvaghet. Får man samma

resultat även i andra studier, så kan skattning av neuroticism inte användas för att identifiera

kvinnor som har hög risk för sekundär värksvaghet.


6

Background

Personality

Personality is an individual’s relatively stable pattern of emotions, behaviors and cognitions that

originate from both biological and environmental factors (Caspi et al., 2005; McCrae et al., 2000).

Personality can be described as consisting of different traits (Bouchard and Loehlin, 2001; Caspi et

al., 2005; John and Gosling, 2000) and these can be measured by both self-reports and by observer-

reports (Pervin, 2000). There are different theories of personality development, one of which is the

five-factor theory (FFT) (McCrae and Costa, 1987), which is well established and often used to

describe personality. The FFT consists of the five factors called the Big Five which are

Neuroticism, Extraversion, Openness, Agreeableness and Conscientiousness. According to the FFT,

personality development mostly comes from intrinsic processes, i.e., genetic composition (Briley

and Tucker-Drob, 2014). However, other models exist, such as social personality models (SPMs)

(Briley and Tucker-Drob, 2014) alternately named the neosocioanalytic or the sociogenomic model

of personality, which are closely linked to social investment theory SPMs. These models highlight

that exogenous factors are the most important, especially the social environment, even though genes

or intrinsic factors provide a foundation for personality development (Briley and Tucker-Drob,

2014).

Stability of personality

Personality is defined to be relatively stable but how stable and for what time interval and what

circumstances? McCrae and Costa have stated that personality becomes mostly stable after the age

of 30 (1990), this being questioned by other researchers (Scollon and Diener, 2006) presenting that

both neuroticism and extraversion are changing over time, both before the age of 30 and after.

Another study the same year (Terracciano et al., 2006) showed similar results as McCrae and Costa

did in 1990, that personalities of the Big five is consistent after 30, and might even be more stable

after that. Whether women’s personality patterns are changing during their first pregnancy has also

been studied. This study (Sjögren et al., 2000) showing statistically significant changes of some

personality factors, among them somatic anxiety that decreased from the time during pregnancy

until post-delivery and showing that breastfeeding lowered the level of somatic anxiety. Their

conclusion was still that personality is mostly stable during pregnancy and lactation but with a

tendency of the pregnant woman becoming more relaxed during this time (Sjögren et al., 2000),

although pre-existing anxiety disorders might actually become more severe during pregnancy (Zar

et al., 2002).


7

Neuroticism

Neuroticism, or negative emotionality, is one of the broader dimensions of personality or a

personality factor that makes a person more likely to experience negative emotions such as anxiety,

fear, irritability, anger and sadness when exposed to stressful situations (Barlow et al., 2014;

Eysenck, 1963). It is also associated with a tendency of not believing in ones capability of handling

difficult or challenging situations (Canli, 2008; Watson et al., 1994). The personality dimension of

neuroticism consists of different personality traits, or subclasses of neuroticism, among them there

are Somatic Trait Anxiety (STA), Psychic Trait Anxiety (PsTA), Stress Susceptibility (SS), Lack of

Assertiveness (LA), Embitterment (E) and Mistrust (M)(Aluoja et al., 2009). Neuroticism has a

strong positive correlation to anxiety sensitivity (AS) (Cox et al., 1999; Hong, 2010; Lilienfeld,

1997) which is sensitivity for experiencing anxiety and which is close to the traits of neuroticism

although not being a trait itself.

The biological explanation of neuroticism is that individuals with higher grade of neuroticism

seems to have lower activation threshold and also greater amygdala activity, a part of the limbic

system of the brain, which could make them have bigger reactions to different stressors

(Cunningham et al., 2010; Eysenck, 1963). There are sex-differences in the levels of neuroticism

showing higher levels of neuroticism in women compared to men (Costa et al., 2001; Vecchione et

al., 2012).

Neuroticism and health outcomes

Neuroticism has been shown to be strongly correlated with some negative health outcomes,

especially mental disorders but also some somatic disorders (Lahey, 2009). In a study comparing

different personalities with comorbidity of eight psychiatric disorders, neuroticism has been shown

to be a vulnerability factor (Khan et al., 2005).

Different personalities have been linked to different coping strategies; Neuroticism seems to be

positively related to disengagement strategies like wishful thinking and the specific coping

strategies emotional support and coping through substance use and is negatively related to another

specific coping strategy, problem solving (Connor-Smith and Flachsbart, 2007). It is not known

whether people scoring high in neuroticism are coping differently with labor compared to other

women and if it the effects the process of labor. Pain perception has also been linked to personality,

whereas neuroticism is thought to be associated with higher pain vigilance meaning greater

attention to pain may exacerbate the pain experienced (Goubert et al., 2004).


8

High neuroticism is associated with higher prevalence of depression and also to greater severity of

the depression, this in a study of older persons (Koorevaar et al., 2013). A study by Wallin Lundell

et al. has shown that a high grade of neuroticism gives an increased risk of posttraumatic stress

disorder (PTSD) or posttraumatic stress symptoms (PTSS) post abortion (Wallin Lundell et al.,

2017). Women with high neuroticism, especially if scoring high in introversion too, are more prone

to get postpartum depression as well (Verkerk et al., 2005).

Uterine inertia and secondary uterine inertia

Uterine inertia is a part of the broader term labor dystocia (LD). To define LD, one first has to

define normal progress of labor. In the normal progress of labor the first phase called the latent

phase is the start-up of labor in which the pregnant woman is starting to have uterine contractions

but they are still not regular, some but not all might be painful. The second phase, which is the

active phase of labor, is defined by 3 factors, 2 of which are required in order to be in active labor.

The 3 factors of active labor are a complete retraction and opening of the cervix by 3-4 cm of the

cervix, at least 3-4 strong and painful uterine contractions in 10 minutes and rupture of the amniotic

membranes. The third phase of labor starts after partus and consists of the delivery of the placenta.

Prolongation of or complications in these three phases is called LD, collecting different problems

during labor in one term. (Cunningham et al., 2018)

There are different definitions for uterine inertia and the one used in this study is the one described

by the Swedish Society of Obstetrics and Gynecology (SFOG) in their handbook of diagnostics

(Pihl, 2010). This handbook is commonly used for diagnostics in Swedish hospitals, and in this

handbook the definition of secondary uterine inertia is no progress during at least 2 hours after an

initially normal progress (Pihl, 2010).

LD often leads to instrumental delivery by for example caesarean section (CS) (Altman and Lydon-

Rochelle, 2006; Selin et al., 2008). In a study of active phase arrest and its outcomes (Henry et al.,

2008) it was seen that LD often led to CS with increased risks of infection (such as

chorionamnionitis and endomyometritis) and postpartum hemorrhage. Similar results have been

shown by Kjaergaard et al. (2009) studying women with LD who were treated with augmentation of

labor, they had a higher rate of postpartum hemorrhage, more often had non-clear amniotic fluid

and the new-borns where more prone to have a low Apgar score at 1 minute. Prolonged second

stage labor causes a greater risk of low Apgar-score after 5 minutes in the new-born (Altman et al.,


9

2015) and is correlated to higher risk of incontinence post-partum, in women who were continent

before pregnancy (Brown et al., 2011).

Risk factors of LD consist of multiparity without previous vaginal delivery, primiparity, gestational

age ≥ 42 weeks and birth weight >4,000 g (Selin et al., 2008). Other risk factors linked to LD are

high (>35-40 years) maternal age (Gilbert et al., 1999; Sheiner et al., 2002), high BMI (Nuthalapaty

et al., 2004), infertility and induction (Sheiner et al., 2002). Epidural analgesia (EDA) is a debated

potential risk factor for LD, it is discussed whether EDA itself could truly lead to LD or if it is

associated to LD because of other factors (Sheiner et al., 2002; Thompson et al., 1998).

Neuroticism and childbirth

Maternal pregnancy anxiety and life event stress was seen in the 1990’s to be associated with lower

birth weight and also to prematurity (Sandman et al., 1997) which Teixiera et al. thought might be

explained by increased uterine artery resistance according to a study in 1999 (Teixeira et al.). In a

later study examining potential adverse birth outcomes of mothers with depressive or anxiety

symptoms (Liou et al., 2016) the authors state that anxiety during pregnancy could predict low birth

weight and similar results were shown in a study of maternal psychological distress (Diego et al.,

2006) where they saw that high mid-gestation cortisol levels predicted low birth weight. Chatzi et

al. examined the broader dimension neuroticism in their study from 2013, in which an increasing

risk of fetal growth restriction seems to exist (Chatzi et al., 2013). High maternal anxiety during

pregnancy is thought to increase the fetal heart rate (Monk et al., 2000).

In a study (Johnston and Brown, 2013) exploring neuroticism’s and extraversion’s relationships,

measured with the Ten Item Personality Measure (Gosling et al., 2003), to different childbirth

outcomes, interventions and complications found that low maternal levels of emotional stability and

low maternal levels of extraversion had a higher risk of CS and risk of experiencing specific

complications during labor.

A connection between maternal fetal attachment and personality has been shown in a study in 2004

(Sjögren et al., 2004) showing a positive association between a tendency to feel guilt and anxiety

and maternal fetal attachment, but on the other hand a negative association with psychic anxiety.

Maternal anxiety during pregnancy seems to have longtime effects for the child as well, children to

mothers who scored high in state anxiety became more impulsive than children to mothers scoring

low in state anxiety when doing cognitive tasks (Bergh et al., 2005).


10

The effects on labor from maternal anxiety was studied already in 1985 (Lederman et al., 1985),

then showing a correlation between maternal anxiety and catecholamine levels, and that the

catecholamine levels had a correlation to duration of labor and in that turn also fetal well-being. In a

study by Saisto et al. (2001) they saw an association between psychological factors such as level of

general maternal anxiety, neuroticism, vulnerability (measured with NEO-Personality Inventory

scales for neuroticism, vulnerability and anxiety) and pregnancy-related anxiety with fear of vaginal

delivery. Similar results have been shown in other studies like in a study by Spice et al. in 2009

(Spice et al., 2009) where they saw that anxiety sensitivity might be a risk factor for elevated fear of

childbirth (FOC) and by Jokić-Begić et al. (2014) who claims that anxiety sensitivity is a factor of

vulnerability for FOC. FOC is thought to increase the risk of LD, premature childbirth and the risk

of needing emergency CS (Adams et al., 2012; Laursen et al., 2009). In summary, results are

conflicting, with some supporting that anxiety has an association to FOC and others saying the

opposite (Sluijs et al., 2012). Neuroticism and FOC seems to have another common denominator,

both being associated to negative life experience (Areskog et al., 1983; Magnus et al., 1993). The

prevalence of FOC seems to be higher in women with depression or anxiety, especially in presence

of both depression and anxiety (Storksen et al., 2012).

Neuroticism and uterine inertia

The idea of this study came from learning about 4 P’s in progress of labor in a lecture about

dystocia and instrumental delivery by Helena Litorp, physician at the Department of Women's and

Children's Health, Uppsala University Hospital. The 4 P’s described were Power, Passenger,

Passage and Psyche/Pain. Given the several adverse perinatal procedures and outcomes uterine

inertia is associated with, we were interested in investigating a possible association with

neuroticism. In the case of a positive association, future studies could investigate if by assessing

neuroticism, health care professional could identify women at high risk and give extra support

during delivery. We hypothesized that high neuroticism would be associated with higher risk for

secondary uterine inertia, since fear of childbirth (Adams et al., 2012; Laursen et al., 2009) is

correlated to prolonged labor, maybe there is a connecting factor of anxiety, typically experienced

by people scoring high in neuroticism.

The second stage of labor could also be thought to get increased risk for prolongation if the

delivering woman has a high grade of neuroticism, since neuroticism makes the individual more

prone to experience anxiety and stress, releasing stress hormones as catecholamines which then

could result in elevated levels (Sandman et al., 1997; Wadhwa et al., 1996). Elevated catecholamine


11

levels are associated with enervated uterine contractility and thought to contribute to prolonged

labor in women with FOC (originally by (Lederman et al., 1978), and cited by Adams et al., 2012).

Aim The aim of this study was to investigate the association between neuroticism and secondary uterine

inertia.


12

Method

Study sample

The material for this project was collected between 2005 and 2012. Personality measures were

distributed as part of several different studies based in Uppsala, Sweden. The original studies

investigated oral contraceptive use (n=118), infertility (n=320), induced abortion (n=1320),

premenstrual mood disorder (n=44) and emotional well-being during pregnancy (n=1017). Most of

the participants lived in Uppsala at the time of data collection, while the remainder were recruited

from Umeå, Örebro, Linköping and Stockholm. Of the original cohort of 2819 women, information

on those 2810 without missing data on personality scores was linked by Statistics Sweden to a

number of Swedish health registers. After the exclusion of women who did not give birth,

multiparas, duplex pregnancies, women who suffered intrauterine fetal demise and the women

starting their delivery with emergency CS or planned CS the final cohort of primiparas consisted of

1864 women. Only primiparas was studied in this project since there are big differences in

prevalence of prolonged labour in primiparas versus multiparas, which is much more prevalent in

primiparas and could then complicate the investigation and interpretation of our study.

Swedish universities Scales of Personality

In the current project, the Swedish universities Scales of Personality (SSP)(Gustavsson et al., 2000)

was used for measuring the level of neuroticism. The SSP is a self-report instrument used to

measure different traits of personality and is a revised and shortened version of the Karolinska

Scales of Personality. It’s designed from the beginning as a diagnostic tool to diagnose Personality

disorders, by measuring different traits and has been validated for measuring neuroticism also in a

Estonian population (Aluoja et al., 2009).

The SSP consists of 91 items, divided into different scales where each scale has 7 items and the

neuroticism dimension of the SSP consists of totally 42 items. The items are different questions

with different statements, and the person answering is supposed to score how well this sues with

themselves. For example, item number 4 that is included in the scale of Lack of Assertiveness is “If

I get treated badly at a restaurant, I have difficulties to assert my opinion”. Then the answering

options goes from 1 to 4 points per item, where the answer 1 is “not at all correct” and 4 is “totally

correct”.

There are 6 subscales for neuroticism in the SSP which are Somatic Trait Anxiety (STA), Psychic

Trait Anxiety (PsTA), Stress Susceptibility (SS), Lack of Assertiveness (LA), Embitterment (E) and


13

Mistrust (M)(Aluoja et al., 2009). The total score of the items in each scale, called “scale-points” is

calculated by summarizing all point within the scale (some of the items points should be inverted

and these ones are marked with a minus-symbol) and then dividing it by the number of items

(which are 7 in each scale). To convert this in to the “standard-point” of the SSP, the T-score, there

is a specific converting table, one for women and one for men (Gustavsson et al., 2000). For the

current analyses, and based on the distribution of neuroticism scores, we compared the upper

quartile of participants with the lowest two quartiles, since it is more clinically applicable if there is

a greater difference between the groups compared.

Swedish Medical Birth Register

In Sweden, information around every pregnancy that has led to delivery is registered in the Swedish

Medical Birth Register (MBR; in Swedish ‘Medicinska födelseregistret’) established by the

National Board of Health and Welfare (‘Socialstyrelsen’) from the year of 1973. The information

collected contains data about the pregnancies, the deliveries and also about the born infants

(Socialstyrelsen).

From the MBR, information on dystocia was extracted, in terms of the International Statistical

Classification of Diseases and Related Health Problems (ICD) from ICD-9 and ICD-10. The

diagnoses included in our outcome “Secondary uterine inertia” are listed in Appendix 2. In the

broader term, the outcome “Uterine inertia” we included both the diagnoses for secondary uterine

inertia and some more, also shown in appendix 2.

Statistical methods

Statistical analyses were performed with the statistical programme SPSS (version 25.0).

Independent T-test was used for parametric numeric data. Chi2-test was used for parametric

nominal data and for non-parametric data we used Mann Whitney-test. Futhermore, multivariable

logistic regression was used in order to adjust for possible confounders and/or mediators.

Potential confounders and mediators

We used Direct Acyclical Graphs (www.dagitty.net) as a tool in order to identify possible

confounders and mediators (see Figure 1: Possible confounders or mediators). We found no

potential confounders in this study but a couple of potential mediators.

For a direct effects model, we adjusted for maternal age and maternal BMI, which we considered as

potential mediators.


14

Figure 1 – Possible confounders or mediators. Showing our Direct Acyclical Graphs-model (created with

www.dagitty.net) with possible confounders or mediators. (BMI= Body Mass Index, EDA= Epidural Analgesia, FOC=

Fear of Childbirth, LGA= Large for Gestational Age)


15

Results In the study, there were 1864 individuals who had answered the SSP completely and whose T-

scores could be statistically analyzed.

The T-scores for neuroticism varied between 194 and 474, the median value was 292 and the mean

value 294.9. 444 (23.8%) of the 1864 women were diagnosed with uterine inertia (see Appendix 1:

Uterine inertia, for included diagnoses) or got contractile stimulation with synthetic oxytocin for

stimulation of labor (excluding the ones starting their delivery with planned or emergency CS). 215

(11.5 %) of the women were diagnosed with secondary uterine inertia (see Appendix 1: Secondary

uterine inertia, for included diagnoses).

Most of the statistical analyses were made by comparing two groups, one group with low

neuroticism and one group with high neuroticism, according to the SSP. The group with low

neuroticism is set to be the first and the second quartile of the neuroticism scale (n=940) and the

group with high neuroticism was the fourth quartile of the neuroticism scale (n=469), leading to a

total of 1409 individuals. This cut off was chosen so that the two groups would be significantly

different in terms of neuroticism, since as mentioned before it is more clinically applicable if there

is a greater difference between the groups compared.

In table 1, the two groups low and high neuroticism are presented, showing their different average

T-scores in neuroticism. Table 1 also shows the difference between the two groups in the different

subclasses of neuroticism STA, PsTA, SS, LA, E and M, also being statistically significant.

Table 1

Differences in measurement of Neuroticism in the two groups low and high neuroticism.

Total n = 1409 Low neuroticism, 1st and 2nd quartile (n=940)

High neuroticism, 4th quartile (n=469)

Neuroticism (T-score), average (SD±) 258.9 (21.0) 354.4 (27.9) STA (T-score), average (SD±) 43.5 (6.2) 57.9 (7.6) PsTA (T-score), average (SD±) 41.9 (5.7) 58.9 (6.9) SS (T-score), average (SD±) 42.9 (6.8) 59.8 (8.6) LA (T-score), average (SD±) 45.8 (7.7) 58.1 (8.6) E (T-score), average (SD±) 43.1 (5.9) 60.7 (9.9) M (T-score), average (SD±) 41.8 (7.0) 59.0 (10.3)


16

The high and low neuroticism groups vary in some maternal factors, showed in table 2. The group

with high neuroticism has a statistically significant lower average age, higher average BMI, a

higher grade of diagnosis with chronic somatic disease and psychiatric morbidity, a lower grade of

highest educational level and fewer of the women of this group lives together with the father of the

child.

Table 2

Descriptive characteristics of the women’s background by low and high neuroticism.

* There were very few cases of diabetes and hypertonia, it might be under represented.

** Chronic somatic disease that we found in this study are chronic kidney disease, ulcerous colitis, Mb Crohn, epilepsy,

hypertonia or diabetes.

*** Psychiatric morbidity that we found in this study is are mood-, anxiety-, stress or eating disorder and alcohol or

substance use disorder at any time point, meaning it could be before pregnancy, during and/or after.

There were also differences in the women’s pregnancies and factors around it showed in table 3.

Statistical significant differences between the high and low neuroticism groups were the numbers of

women diagnosed with gestational diabetes and the use of anxiolytic during pregnancy, both higher



p-value

Age, average (SD±) 28.5 (4.8) 26.3 (5.50) 0.000 BMI, average (SD±) 23.7 (3.7) 24.6 (4.6) 0.006 BMI (categories): Underweight (BMI < 18.5), n (%) 12 (1.3) 8 (1.7) Normal weight (BMI 18.5-24.9), n (%) 578 (61.5) 248 (52.9) Overweight (BMI 25-29.9), n (%) 167 (17.8) 96 (20.5) Obese (BMI ³ 30.0), n (%) 58 (6.2) 58 (12.4) "missing" 125 (13.3) 59 (12.6) Diabetes*, n (%) 0 (0.0) 2 (0.4) 0.045 Hypertonia*, n (%) 3 (0.3) 2 (0.4) 0.750 Chronic somatic disease **, n (%) 8 (0.9) 11 (2.3) 0.022 Smoking 3 months before or during pregnancy, n (%)

132(14.0) 131 (27.9) 0.000

Smoking during pregnancy, n (%) 61 (6.5) 67 (14.3) 0.000 Snuff use 3 months before or during pregnancy, n (%)

46 (4.9) 26 (5.5) 0.592

Snuff use during pregnancy, n (%) 11 (1.2) 6 (1.3) 0.869 Psychiatric morbidity (any time-point) ***, n (%) 51 (5.4) 74 (15.8) 0.000 Previous depression, n (%) 12 (1.3) 21 (4.5) 0.000 Previous anxiety disorder, n (%) 8 (0.9) 15 (3.2) 0.001 Previous stress reactions, n (%) 4 (0.4) 5 (1.1) 0.155 Previous bipolar disorder, n (%) 4 (0.4) 3 (0.6) 0.590 Involuntary childlessness ³1 year, n (%) 158 (16.8) 82 (17.5) 0.751 Highest educational level – Higher than secondary school, n (%)

674 (71.7) 224 (47.8) 0.000

Family situation – Lives together with the father of the child, n (%)

858 (91.3) 376 (80.2) 0.000


17

in the group with high neuroticism, and gender of the child which was more often a girl in the group

with high neuroticism. The groups did not differ in either start or end of the delivery and neither in

pain relief with epidural anesthesia or spinal anesthesia.

Table 3

Pregnancy and delivery-associated variables, by low and high neuroticism

*There were very few cases of gestational diabetes, EDA, spinal anesthesia and general anesthesia in this material, it

might be under represented.

No statistically significant association between neuroticism and secondary uterine inertia was

shown, neither with the broader term uterine inertia.

Table 4

Uterine inertia and secondary uterine inertia in the two groups of low and high neuroticism.

*Included ICD-codes in ‘Uterine inertia’ and ‘Secondary uterine inertia’ are described in Appendix 1.

Each subclass of neuroticism was also tested for potential association with secondary uterine

inertia, showed in table 5. The subclasses STA, PsTA, SS, LA, E and M were all divided into

groups with low or high T-scores for the different traits, comparing the low and high group in



p-value

Gestional diabetes*, n (%) 2 (0.2) 5 (1.1) 0.032 Gestational diabetes or LGA, n (%) 21 (2.2) 16 (3.4) 0.193 Gestational HT, n (%) 25 (2.7) 17 (3.6) 0.315 Gestational HT or preeklampsia, n (%) 54 (5.7) 34 (7.2) 0.271 Involuntary childlessness ³ 1 year, n (%) 158 (16.8) 82 (17.5) 0.751 Start of delivery – Spontaneous, n (%) 767 (81.6) 380 (81.0) 0.795 End of delivery – Vaginal delivery, n (%) 694 (73.8) 364 (77.6) 0.122 Epidural anesthesia*, n (%) 96 (10.2) 48 (10.2) 0.99 Spinal anesthesia*, n (%) 11 (1.2) 8 (1.7) 0.411 General anesthesia*, n (%) 0 (0.0) 1 (0.2) Pregnancy length (weeks), average (SD±) 39.52 (1.9) 39.57 (1.6) Pregnancy length over 40 weeks, n (%) 260 (27.7) 142 (30.3) 0.311 Antidepressant or anxiolytic during pregnancy, n (%) 10 (1.1) 22 (4.7) 0.000 Gender of the child – Girl, n (%) 422 (44.9) 238 (50.7) 0.038



p-value

Uterine inertia*, n (%) 233 (24.8) 107 (22.8) 0.415 Secondary uterine inertia*, n (%) 104 (11.1) 52 (11.1) 1.0


18

outcome of secondary uterine inertia. The result among these did not show any statistically

significant differences among the groups.

Table 5

Secondary uterine inertia within the different subclasses of neuroticism. Neuroticism subclasses Secondary uterine inertia

in the low-group*, n (%)

Secondary uterine inertia

in the high-group**, n (%)

p-value

Somatic Trait Anxiety

(n=1478)

103 (10.5) 60 (12.1) 0.380

Psychic Trait Anxiety

(n=1451)

110 (11.3) 62 (12.5) 0.388

Stress Susceptibility

(n=1530)

117 (11.3) 63 (12.7) 0.448

Lack of Assertiveness

(n = 1524)

116 (11.6) 53 (10.1) 0.392

Embitterment

(n = 1611)

123 (12.3) 65 (10.6) 0.338

Mistrust

(n = 1665)

129 (11.6) 66 (11.8) 0.936

* The low-group in each subclass consists of the first and second quartile of each subclass’ T-score.

** The high-group in each subclass consists of the fourth quartile of each subclass’ T-score.

The hypothesis was also tested with logistic regression comparing the outcome of secondary uterine

inertia with level of neuroticism in the two groups low and high neuroticism, showing an odds ratio

1.002 (confidence interval (CI) 95% 0.704 – 1.427) with a non-significant p-value of 0.989. When

adjusting for age and BMI (both of them factors affecting uterine inertia and significantly different

between the two groups) still no statistically significant difference was seen, with odds ratio 1.066

(CI 95% 0.721 – 1.577) p-value 0.748. Logistic regression was also used for the whole sample of

1864 women, without excluding the third quartile in the distribution of neuroticism, but showed

also no association.


19

Discussion

Main findings of the study

The result of this study was that there was no significant association between neuroticism and

secondary uterine inertia.

In Sweden 35,6% of primiparas get diagnosed with prolonged labor (Nystedt and Hildingsson,

2014) and to detect just a minor difference like for example 0,5% we would need as many as

225494 women in this study to reach the power of 80% calculated by a power-calculation at

www.infovoice.se (provided by Department of Public Health and Community, Medicine Institute of

Medicine, Sahlgrenska Academy, University of Gothenburg) which might point at this study having

to few participants. On the other hand, there were enough participants in this study to find a greater

difference as for example a 5% increase of prolonged labor which according to calculation would

have needed 1480 participating women to reach the same power. One could also discuss whether a

difference that is very small would be of any clinical use.

There are few studies on this topic, but there is one British study about both neuroticism’s and

extraversion’s association to delivery outcome (Johnston and Brown, 2013). Johnston and Brown

do not especially investigate whether neuroticism has an association to secondary uterine inertia but

they do look into the problem with prolonged labor. A big difference between their study and our is

that they let the women describe their labor themselves, whilst we are relying on the Swedish MBR

instead. They used a different personality measurement tool than the SSP, the tool used by Johnston

and Brown is called Ten Item Personality Measure and is also a self-report measurement tool. The

Ten Item Personality Measure is also focused on the Big Five, but is a short measure of personality

with fewer questions than the SSP. Another difference is that they have a more heterogeneous

material sample than we do, considering that they include for example both primiparas and

multiparas. Since their study is performed in the United Kingdom it is a similar setting as for our

study with Swedish material considering health care since it is also a publicly paid healthcare

system like Sweden, providing care for everyone independent of socioeconomic status. In their

study, they found that the mothers scoring low in emotional stability (in other words high in

neuroticism), more often needed CS or even emergency CS and according to their results

complications like failure to progress leading to augmentation of labor, assisted delivery and fetal

distress was associated to lower emotional stability, which is not replicated in our study. It can be

speculated that in the Swedish setting, all women get adequate emotional and practical support from

the staff, so that even mothers with high neuroticism feel protected and calm during delivery.


20

It is plausible that an association between neuroticism and secondary uterine inertia could have

been found since neuroticism could be associated to FOC, which in turn is associated to LD or

prolonged labor, not surprising if considering FOC as an anxiety disorder or in some cases a phobic

disorder, anxiety disorders and phobic disorders being common among individuals scoring high in

neuroticism (Clark et al., 1994; Lahey, 2009). Women with FOC have been described as generally

anxious (Areskog et al., 1983), and to have lack of self-esteem (Saisto et al., 2001), which sues well

with the personality dimension of neuroticism or low emotional stability.

In the studies showing an association between FOC and LD (Adams et al., 2012; Laursen et al.,

2009), the studies are both studies with a numerous material made in Norway respectively

Denmark, two Nordic countries which are quite similar to Sweden in many aspects. Despite the

difference that these studies investigate FOC instead of personality, they have results that, if FOC

had been measured in our material, we thought could be seen in our material too. In the Danish

study by Laursen et al. they only included healthy nulliparous women, with spontaneous onset of

labor after gestational week 37 with no obstetrical risk factors. Similar to that, the Norwegian study

excluded multiple pregnancy, delivery before 37 gestational weeks, delivery with CS, or non-

cephalic presentation at delivery, thus not excluding multiparas like in our study and like Laursen et

al. Their design with inclusion and exclusion criteria are much like our study, and they both have

information from the MBR in their respective country.

Pathophysiologically one could think that the second stage of labor could have increased risk to be

prolonged if the delivering woman has a high grade of neuroticism, since neuroticism makes the

individual more prone to experience anxiety and stress, releasing stress hormones as catecholamines

which then could result in elevated levels (Sandman et al., 1997; Wadhwa et al., 1996). Elevated

catecholamine levels are associated to enervated uterine contractility and thought to contribute to

prolonged labor in women with FOC (originally by (Lederman et al., 1978), and cited by Adams et

al., 2012).

Strengths and limitations

A great strength of our study is novelty. It investigates a hypothesis that has only partly been tested

before. Other studies similar to this one rather look in terms of delivery outcomes due to maternal

anxiety, not the broader dimensions of personality like neuroticism.


21

The number of participants increases the power of the study, and the large number of variables

about the women is also strength. The MBR is a secure source of information, with high validity.

We also restricted analyses to primiparas, with single pregnancy and with spontaneous delivery

start, having a homogeneous sample which could help reduce possible confounding factors but of

course it does not show the heterogeneous reality of women in labor.

The SSP, is a validated instrument for measuring neuroticism and has also been validated in other

countries than Sweden. A major limitation of this study though, is that we do not know when these

women have answered the SSP (before or after their delivery), especially since it is questionable

how stable a woman’s personality is going from not pregnant to pregnant and finally postpartum.

Thinking that elevated catecholamines might contribute to prolonged labor (originally by

(Lederman et al., 1978), and cited by Adams et al., 2012) it would have been interesting to have

measured this.

Another limitation is that the women’s fear of childbirth was not assessed, since it is a factor that

might affect the final outcome and there are validated measuring tools like the Wijma Delivery

Expectancy/Experience Questionnaire (W-DEQ) (Wijma et al., 1998) or the Childbirth Fear – Prior

to Pregnancy (CFPP) scale (Stoll et al., 2016), which could have been used in this study. The

women’s fear of childbirth is an interesting factor to investigate, concerning neuroticism, since the

common feeling of anxiety among individuals scoring high in neuroticism, could be manifested as

FOC during pregnancy, which is also a form of anxiety.

The amount of social support was not accounted for either, something that could possibly affect the

result of our study. In our study, we only have the family situation factor of living or not living with

the father of the child, describing part of how the pregnant woman’s social support is, but not all. A

woman not living with the father of the child could still have excellent social support of other

individuals in their life like other family members, friends or maybe a new partner. Living with the

father of the child could also possibly be negative for the woman’s social support if the man is not

supportive, abusive or have other problems possibly affecting the pregnant woman’s feeling of

security and stability in life. We do not have information of how much support the pregnant woman

has had during pregnancy or delivery by the medical staff either. One could assume that a woman

showing more need of support also should receive a greater amount of support by the staff.


22

In this study, we only include the women who got the diagnosis secondary uterine inertia according

to ICD-8, -9 and -10, which might not cover all of the true cases of secondary uterine inertia as it is

commonly under diagnosed. We did not examine the women’s partograms, which could have been

a way to see the exact number of cases of secondary uterine inertia (and then it would be possible to

list the number of cases diagnosed by the same person). On the other hand, even if we might not

have all of the true cases of secondary uterine inertia, we could assume that the ones not getting the

diagnose even if truly affected by it probably are the same percentage of women in both of the

groups since the data about it comes from the same source (MBR).

One could question whether this study design would get the same result in a different country than

Sweden, especially in a country where health care is not free for everyone to receive. Considering

that individuals with a high grade of neuroticism has a lower educational level, often indicating a

lower socioeconomically status, these individuals in other countries might have a lower grade of

health care availability. This could also affect the amount of support the woman gets during labor

(in Swedish health care the support is always supposed to be given to women during labor).

Swedish midwives have education in supporting all the way through pregnancy and labor and if

FOC is discovered the woman is offered extra support; maybe this is very beneficial for women

with high grade of neuroticism and it might even erase the possible difference between women

scoring low and high in neuroticism. I might just be so that the system in Sweden provides

maximum support to women during delivery, and also in the time before it, so that the women with

high neuroticism feel as comfortable and at ease as women scoring lower in neuroticism, or at least

in the same extent as them.

Conclusions

In the current study, there was no association between neuroticism and the outcome secondary

uterine inertia. If this is replicated in other study samples, results point to there not being a use for

assessment of neuroticism for the identification of individuals for high risk of secondary uterine

inertia.

Future research

If one wants to examine this hypothesis in the future it could be of interest to measure each

woman’s grade of neuroticism multiple times, showing if the result is stable over time during

pregnancy. It could also be of great interest to measure the women’s fear of childbirth, a couple of

times before and after delivery.


23

Another question one could examine whether there is a difference between women with high grade

of neuroticism divided into groups with much or little social support during pregnancy and delivery

in the outcome secondary uterine inertia? To look into this question, one would need to use some

kind of measurement of social support.

This study should also be performed in different settings than Sweden. Sweden being a rather

unique country according to our health care system, which is the same for everyone no matter of

socioeconomic status and with a great health care availability. But also since lots of other factors

care can differ like the environment, genetics, information about pregnancy and general health.


24

Acknowledgements I want to give a great thank you to my supervisor Alkistis for giving me this project, for support and

interesting discussions and to my three co-supervisors Cathrine, Emma and Emma, who have

helped me a lot during this project and for giving me the tools to work with something so new and

challenging for me.

Thank you, Fanny, and Lollo, who has been answering a lot of little (but still very important)

questions among the way and for all the good lunch breaks!

And also, a big thank you to my love Alexander who has been wonderfully supportive all along.


25

References 1. Adams, S., Eberhard-Gran, M., and Eskild, A. (2012). Fear of childbirth and duration of

labour: a study of 2206 women with intended vaginal delivery. BJOG Int. J. Obstet. Gynaecol. 119, 1238–1246.

2. Altman, M.R., and Lydon-Rochelle, M.T. (2006). Prolonged Second Stage of Labor and Risk of Adverse Maternal and Perinatal Outcomes: A Systematic Review. Birth 33, 315–322.

3. Altman, M., Sandström, A., Petersson, G., Frisell, T., Cnattingius, S., and Stephansson, O. (2015). Prolonged second stage of labor is associated with low Apgar score. Eur. J. Epidemiol. 30, 1209–1215.

4. Aluoja, A., Voogne, H., Maron, E., Gustavsson, J.P., Võhma, Ü., and Shlik, J. (2009). Personality traits measured by the Swedish universities Scales of Personality: Factor structure and position within the five-factor model in an Estonian sample. Nord. J. Psychiatry 63, 231–236.

5. Areskog, B., Uddenberg, N., and Kjessler, B. (1983). Background factors in pregnant women with and without fear of childbirth. J. Psychosom. Obstet. Gynecol. 2, 102–108.

6. Barlow, D.H., Ellard, K.K., Sauer-Zavala, S., Bullis, J.R., and Carl, J.R. (2014). The Origins of Neuroticism. Perspect. Psychol. Sci. 9, 481–496.

7. Bergh, B.R.H.V. den, Mennes, M., Oosterlaan, J., Stevens, V., Stiers, P., Marcoen, A., and Lagae, L. (2005). High antenatal maternal anxiety is related to impulsivity during performance on cognitive tasks in 14- and 15-year-olds. Neurosci. Biobehav. Rev. 29, 259–269.

8. Bouchard, T.J., and Loehlin, J.C. (2001). Genes, Evolution, and Personality. Behav. Genet. 31, 243–273.

9. Briley, D.A., and Tucker-Drob, E.M. (2014). Genetic and environmental continuity in personality development: A meta-analysis. Psychol. Bull. 140, 1303–1331.

10. Brown, S., Gartland, D., Donath, S., and MacArthur, C. (2011). Effects of prolonged second stage, method of birth, timing of caesarean section and other obstetric risk factors on postnatal urinary incontinence: an Australian nulliparous cohort study. BJOG Int. J. Obstet. Gynaecol. 118, 991–1000.

11. Canli, T. (2008). Toward a neurogenetic theory of neuroticism. Ann. N. Y. Acad. Sci. 1129, 153–174.

12. Caspi, A., Roberts, B.W., and Shiner, R.L. (2005). Personality Development: Stability and Change. Annu. Rev. Psychol. 56, 453–484.

13. Chatzi, L., Koutra, K., Vassilaki, M., Vardiampasis, A., Georgiou, V., Koutis, A., Lionis, C., Bitsios, P., and Kogevinas, M. (2013). Maternal personality traits and risk of preterm birth and fetal growth restriction. Eur. Psychiatry 28, 213–218.


26

14. Clark, L.A., Watson, D., and Mineka, S. (1994). Temperament, personality, and the mood and anxiety disorders. J. Abnorm. Psychol. 103, 103–116.

15. Connor-Smith, J.K., and Flachsbart, C. (2007). Relations between personality and coping: a meta-analysis. J. Pers. Soc. Psychol. 93, 1080–1107.

16. Costa, P.T., Terracciano, A., and McCrae, R.R. (2001). Gender differences in personality traits across cultures: Robust and surprising findings. J. Pers. Soc. Psychol. 81, 322–331.

17. Cox, B.J., Borger, S.C., Taylor, S., Fuentes, K., and Ross, L.M. (1999). Anxiety sensitivity and the five-factor model of personality. Behav. Res. Ther. 37, 633–641.

18. Cunningham, F.G., Leveno, K.J., Bloom, S.L., Dashe, J.S., Hoffman, B.L., Casey, B.M., and Spong, C.Y. (2018). Abnormal Labor. In Williams Obstetrics, (New York, NY: McGraw-Hill Education).

19. Cunningham, W.A., Arbuckle, N.L., Jahn, A., Mowrer, S.M., and Abduljalil, A.M. (2010). Aspects of neuroticism and the amygdala: chronic tuning from motivational styles. Neuropsychologia 48, 3399–3404.

20. Diego, M., Miguel A Diego, Nancy A Jones, Tiffany Field, and Maria Hernandez-Reif (2006). Maternal Psychological Distress, Prenatal Cortisol, and Fetal Weight. Psychosom. Med. 68.

21. Eysenck, H.J. (1963). Biological Basis of Personality. Nature 199, 1031–1034. 22. Gilbert, W.M., Nesbitt, T.S., and Danielsen, B. (1999). Childbearing Beyond Age 40:

Pregnancy Outcome in 24,032 Cases. Obstet. Gynecol. 93, 9–14.

23. Gosling, S.D., Rentfrow, P.J., and Swann, W.B. (2003). A very brief measure of the Big-Five personality domains. J. Res. Personal. 37, 504–528.

24. Goubert, L., Crombez, G., and Van Damme, S. (2004). The role of neuroticism, pain catastrophizing and pain-related fear in vigilance to pain: a structural equations approach. Pain 107, 234–241.

25. Gustavsson, J.P., Bergman, H., Edman, G., Ekselius, L., Von Knorring, L., and Linder, J. (2000). Swedish universities Scales of Personality (SSP): construction, internal consistency and normative data. Acta Psychiatr. Scand. 102, 217–225.

26. Henry, D.E.M., Cheng, Y.W., Shaffer, B.L., Kaimal, A.J., Bianco, K., and Caughey, A.B. (2008). Perinatal Outcomes in the Setting of Active Phase Arrest of Labor: Obstet. Gynecol. 112, 1109–1115.

27. Hong, R.Y. (2010). Neuroticism, Anxiety Sensitivity Thoughts, and Anxiety Symptomatology: Insights from an Experience-Sampling Approach. Cogn. Ther. Res. N. Y. 34, 254–262.

28. John, O.P., and Gosling, S.D. (2000). Personality traits. In Encyclopedia of Psychology, Vol. 6., A.E. Kazdin, ed. (Washington: American Psychological Association), pp. 140–144.

29. Johnston, R.G., and Brown, A.E. (2013). Maternal trait personality and childbirth: The role of extraversion and neuroticism. Midwifery 29, 1244–1250.


27

30. Jokić-Begić, N., Zigić, L., and Nakić Radoš, S. (2014). Anxiety and anxiety sensitivity as

predictors of fear of childbirth: different patterns for nulliparous and parous women. J. Psychosom. Obstet. Gynaecol. 35, 22–28.

31. Khan, A.A., Jacobson, K.C., Gardner, C.O., Prescott, C.A., and Kendler, K.S. (2005). Personality and comorbidity of common psychiatric disorders. Br. J. Psychiatry 186, 190–196.

32. Kjaergaard, H., Olsen, J., Ottesen, B., and Dykes, A.-K. (2009). Incidence and outcomes of dystocia in the active phase of labor in term nulliparous women with spontaneous labor onset. Acta Obstet. Gynecol. Scand. 88, 402–407.

33. Koorevaar, A.M.L., Comijs, H.C., Dhondt, A.D.F., van Marwijk, H.W.J., van der Mast, R.C., Naarding, P., Oude Voshaar, R.C., and Stek, M.L. (2013). Big Five personality and depression diagnosis, severity and age of onset in older adults. J. Affect. Disord. 151, 178–185.

34. Lahey, B.B. (2009). Public Health Significance of Neuroticism. Am. Psychol. 64, 241–256.

35. Laursen, M., Johansen, C., and Hedegaard, M. (2009). Fear of childbirth and risk for birth complications in nulliparous women in the Danish National Birth Cohort. BJOG Int. J. Obstet. Gynaecol. 116, 1350–1355.

36. Lederman, R.P., Lederman, E., Work, B.A., and McCann, D.S. (1978). The relationship of maternal anxiety, plasma catecholamines, and plasma cortisol to progress in labor. Am. J. Obstet. Gynecol. 132, 495–500.

37. Lederman, R.P., Lederman, E., Bruce, W., and McCann, D.S. (1985). Anxiety and epinephrine in multiparous women in labor: Relationship to duration of labor and fetal heart rate pattern. Am. J. Obstet. Gynecol. 153, 870–877.

38. Lilienfeld, S.O. (1997). The relation of anxiety sensitivity to higher and lower order personality dimensions: Implications for the etiology of panic attacks. J. Abnorm. Psychol. 106, 539–544.

39. Liou, S.-R., Wang, P., and Cheng, C.-Y. (2016). Effects of prenatal maternal mental distress on birth outcomes. Women Birth 29, 376–380.

40. Magnus, K., Diener, E., Fujita, F., and Pavot, W. (1993). Extraversion and neuroticism as predictors of objective life events: A longitudinal analysis. J. Pers. Soc. Psychol. 65, 1046–1053.

41. McCrae, R.R. (1990). Personality in adulthood. Personal. Adulthood.

42. McCrae, R.R., and Costa, P.T. (1987). Validation of the five-factor model of personality across instruments and observers. J. Pers. Soc. Psychol. 52, 81–90.

43. McCrae, R.R., Costa, P.T.J., Ostendorf, F., Angleitner, A., Hřebíčková, M., Avia, M.D., Sanz, J., Sánchez-Bernardos, M.L., Kusdil, M.E., Woodfield, R., et al. (2000). Nature over nurture: Temperament, personality, and life span development. J. Pers. Soc. Psychol. 78, 173–186.


28

44. Monk, C., Fifer, W.P., Myers, M.M., Sloan, R.P., Trien, L., and Hurtado, A. (2000).

Maternal stress responses and anxiety during pregnancy: Effects on fetal heart rate. Dev. Psychobiol. 36, 67–77.

45. Nuthalapaty, F.S., Rouse, D.J., and Owen, J. (2004). The association of maternal weight with cesarean risk, labor duration, and cervical dilation rate during labor induction. Obstet. Gynecol. 103, 452–456.

46. Nystedt, A., and Hildingsson, I. (2014). Diverse definitions of prolonged labour and its consequences with sometimes subsequent inappropriate treatment. BMC Pregnancy Childbirth 14, 233.

47. Pervin, L.A. (2000). Personality. In Encyclopedia of Psychology, Vol. 6., A.E. Kazdin, ed. (Washington: American Psychological Association), pp. 100–106.

48. Pihl, K. (2010). Diagnoshandbok för kvinnosjukvården 2010 (Stockholm: Svensk förening för obstetrik och gynekologi (SFOG)).

49. Saisto, T., Salmela-Aro, K., Nurmi, J.E., and Halmesmäki, E. (2001). Psychosocial characteristics of women and their partners fearing vaginal childbirth. BJOG Int. J. Obstet. Gynaecol. 108, 492–498.

50. Sandman, C.A., Wadhwa, P.D., Chicz-DeMet, A., Dunkel-Schetter, C., and Porto, M. (1997). Maternal Stress, HPA Activity, and Fetal/Infant Outcomea. Ann. N. Y. Acad. Sci. 814, 266–275.

51. Scollon, C.N., and Diener, E. (2006). Love, work, and changes in extraversion and neuroticism over time. J. Pers. Soc. Psychol. 91, 1152–1165.

52. Selin, L., Wallin, G., and Berg, M. (2008). Dystocia in labour – risk factors, management and outcome: a retrospective observational study in a Swedish setting. Acta Obstet. Gynecol. Scand. 87, 216–221.

53. Sheiner, E., Levy, A., Feinstein, U., Hallak, M., and Mazor, M. (2002). Risk factors and outcome of failure to progress during the first stage of labor: a population-based study*. Acta Obstet. Gynecol. Scand. 81, 222–226.

54. Sjögren, B., Widström, A.M., Edman, G., and Uvnaus-Moberg, K. (2000). Changes in personality pattern during the first pregnancy and lactation. J. Psychosom. Obstet. Gynecol. 21, 31–38.

55. Sjögren, B., Edman, G., Widström, A.M., Mathiesen, A.S., and Uvnäs-Moberg, K. (2004). Maternal foetal attachment and personality during first pregnancy. J. Reprod. Infant Psychol. 22, 57–69.

56. Sluijs, A.-M., Cleiren, M.P.H.D., Scherjon, S.A., and Wijma, K. (2012). No relationship between fear of childbirth and pregnancy-/delivery-outcome in a low-risk Dutch pregnancy cohort delivering at home or in hospital. J. Psychosom. Obstet. Gynaecol. 33, 99–105.

57. Socialstyrelsen In English – the Swedish Medical Birth Register.


29

58. Spice, K., Jones, S.L., Hadjistavropoulos, H.D., Kowalyk, K., and Stewart, S.H. (2009). Prenatal fear of childbirth and anxiety sensitivity. J. Psychosom. Obstet. Gynaecol. 30, 168–174.

59. Stoll, K., Hauck, Y., Downe, S., Edmonds, J., Gross, M.M., Malott, A., McNiven, P., Swift, E., Thomson, G., and Hall, W.A. (2016). Cross-cultural development and psychometric evaluation of a measure to assess fear of childbirth prior to pregnancy. Sex. Reprod. Healthc. Off. J. Swed. Assoc. Midwives 8, 49–54.

60. Storksen, H.T., Eberhard-Gran, M., Garthus-Niegel, S., and Eskild, A. (2012). Fear of childbirth; the relation to anxiety and depression: Fear of childbirth and mental health. Acta Obstet. Gynecol. Scand. 91, 237–242.

61. Teixeira, J.M., Fisk, N.M., and Glover, V. (1999). Association between maternal anxiety in pregnancy and increased uterine artery resistance index: cohort based study. BMJ 318, 153–157.

62. Terracciano, A., Costa, P.T., and McCrae, R.R. (2006). Personality Plasticity After Age 30. Pers. Soc. Psychol. Bull. 32, 999–1009.

63. Thompson, T.T., Thorp, J.M., Mayer, D., Kuller, J.A., and Bowes, W.A. (1998). Does epidural analgesia cause dystocia? J. Clin. Anesth. 10, 58–65.

64. Vecchione, M., Alessandri, G., Barbaranelli, C., and Caprara, G. (2012). Gender differences in the Big Five personality development: A longitudinal investigation from late adolescence to emerging adulthood. Personal. Individ. Differ. 53, 740–746.

65. Verkerk, G.J.M., Denollet, J., Van Heck, G.L., Van Son, M.J.M., and Pop, V.J.M. (2005). Personality factors as determinants of depression in postpartum women: a prospective 1-year follow-up study. Psychosom. Med. 67, 632–637.

66. Wadhwa, P.D., Dunkel-Schetter, C., Chicz-DeMet, A., Porto, M., and Sandman, C.A. (1996). Prenatal Psychosocial Factors and the Neuroendocrine Axis in Human Pregnancy: Psychosom. Med. 58, 432–446.

67. Wallin Lundell, I., Sundström Poromaa, I., Ekselius, L., Georgsson, S., Frans, Ö., Helström, L., Högberg, U., and Skoog Svanberg, A. (2017). Neuroticism-related personality traits are associated with posttraumatic stress after abortion: findings from a Swedish multi-center cohort study. BMC Womens Health 17, 96.

68. Watson, D., Clark, L.A., and Harkness, A.R. (1994). Structures of personality and their relevance to psychopathology. J. Abnorm. Psychol. 103, 18–31.

69. Wijma, K., Wijma, B., and Zar, M. (1998). Psychometric aspects of the W-DEQ; a new questionnaire for the measurement of fear of childbirth. J. Psychosom. Obstet. Gynecol. 19, 84–97.

70. Zar, M., Wijma, K., and Wijma, B. (2002). Relations between anxiety disorders and fear of childbirth during late pregnancy. Clin. Psychol. Psychother. 9, 122–130.


30

Appendices Appendix 1 – ICD codes Secondary uterine inertia

- ICD-8 657,1 Secondary uterine inertia

- ICD-9 661B Secondary hypotonic uterine inertia

- ICD-9 662C Prolonged second stage of labour

- ICD-10 062.1 Secondary uterine inertia (Arrested active phase of labour, Secondary

hypotonic uterine dysfunction)

- ICD-10 063.1 Prolonged second stage (of labour)

Uterine inertia

- ICD-8 Code: 657,1 Secondary uterine inertia

- ICD-9 661A Hypotonic uterine inertia

- ICD-9 661B Secondary hypotonic uterine inertia

- ICD-9 662C Prolonged second stage of labour

- ICD-10 062.0 Primary inadequate contractions (Failure of cervical dilatation, Primary

hypotonic uterine dysfunction, Uterine inertia during latent phase of labour)

- ICD-10 062.1 Secondary uterine inertia (Arrested active phase of labour, Secondary

hypotonic uterine dysfunction)

- ICD-10 062.2 Other uterine inertia (Atony of uterus, Desultory labour, Hypotonic uterine

dysfunction NOS, Irregular labour, Poor contractions, Uterine inertia NOS)

- ICD-10 062.8 Other abnormalities of forces of labour

- ICD-10 062.9 Abnormality of forces of labour, unspecified

- ICD-10 063.0 Prolonged first stage (of labour)

- ICD-10 063.1 Prolonged second stage (of labour)

- ICD-10 063.9 Long labour, unspecified (prolonged labour NOS)

- ICD-10 DT037 Oxytocintillförsel för stimulering av värkarbete


31

Appendix 2 – SSP manual

the association between neuroticism and secondary uterine inertia1318418/... · 2019. 5. 27. · in...

Documents