Obesity in Pregnancy: Is it a Big Problem?

Joseph R. Biggio, M.D.

Objectives

• Become familiar with the physiologic alterations in obese pregnant women

• Understand the medical and obstetric complications associated with obesity in pregnancy

• Become familiar with long-term consequences of maternal obesity for the woman and her offspring

• Discuss risk-reducing strategies for obesity-related complications

Obesity

• Major medical and public health problem

• Significant morbidity and mortality

• Health care expenditures: • By 2030, 16-18% of all healthcare

expenditures related

Wang et al, Obesity 2008

2000

Obesity Trends* Among U.S. AdultsBRFSS, 1990, 2000, 2010

(*BMI 30, or about 30 lbs. overweight for 5’4” person)

2010

1990

No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

15%–<20% 20%–<25% 25%–<30% 30%–<35% ≥35%

Obesity Among U.S. Adults BRFSS, 2013

CA

MT

ID

NVUT

AZNM

WY

WA

OR

CO

NE

ND

SD

TX

OK

KS

IA

MN

AR

MO

LA

MI

IN

KY

ILOH

TN

MS AL

WI

PA

WV

SC

VA

NC

GA

FL

NY

VT

ME

HI

AK

NHMARICTNJDEMDDC

PRGUAM

Obesity in Women

NHANES, Health E-Stat, Fryar et al, CDC NCHS, Sept 2014

BMI 2001-02 2011-1225-29.9 28.2 29.730-39.9 33.2 36.1>40 6.5 8.3

Obesity: Race/ethnicity effect

NHANES, Health E-Stat, Fryar et al, CDC NCHS, Sept 2014; NCVS, Flegal et al, 2010

2011-12Non-Hispanic White 32.8Non-Hispanic Black 56.6Asian 11.4Hispanic 44.4

• 75% of AA women BMI >25

Economic Costs—Medical Care• Increased utilization of resources

• Prenatal visits• Ultrasounds and fetal surveillance• Medications dispensed

• Increased• Comorbid conditions• Hospitalizations• Prolonged hospital stays• Maternal and neonatal ICU admissions

• Adds approximately $5.4-6 billion annually in healthcare cost in UK

Chu et al., NEJM, 2008; Heslehurst, Obes Rev 2008; Dennison et al., BJOG. 2009

Physiologic Changes: Cardiovascular

• Blood volume, Cardiac output increase in proportion to fat and tissue mass• CO increase 30-35 ml/min per 100 gm fat

• Diminished progesterone-induced vascular compliance• Increase risk for LV hypertrophy• Intimal hyperplasia and medial thickening

Veille JC et al, AJOG 1994; Perlow J, Obstetric Intensive Care Manual, 2003

Physiologic Changes: Pulmonary

PO2, chest wall/lung compliance• 50% lower compliance than non-obese• Work of breathing 3x higher than normal

• Risk for sleep apnea• Pulmonary hypertension

Juvin et al, Anesth Analges, 2003; Perlow J, Obstetric Intensive Care Manual, 2003

OSA, Co-morbidities & Outcomes

CHTN Diabetes Asthma05

1015202530354045

44

3033

11 9 93 1

8

OSAObeseNormal Wt

Louis et al, AJOG 2010; 202(3):261

Pre-E <37 wk <32 wk Cesarean0

10

20

30

40

50

60

19

30

12

58

11 10

1

40

712

4

15

Antenatal Complications

• Infertility

• Spontaneous Abortion

• Congenital Malformations

• Perinatal Mortality

Infertility• Fecundity reduced

• Overweight 8%• Obese 18%

• Possible Etiologies• HPO axis disruption• Increased leptin• Insulin resistance with androgen, SHBG• fat, estrone• Endometrial abnormalities

Gesink et al, Hum Repro, 2007; Pasquali et al, Hum Repro Update, 2003; Haslam, Lancet, 2005

Spontaneous Abortion

• Increased loss rateOR 1.7 (1.3 – 2.3)

• After ovulation induction: OR 5.1 (1.8 – 14.8)

• ? Related to estrogen and luteal phase defect with progesterone

• ? diabetesMetwally et al, Fertil Ster, 2008

Congenital Anomaly and Obesity

• Multiple studies demonstrate increased risk• Multiple different types involved

• Dose-response relationship

• Undiagnosed diabetes suggested as potential contributor

Stothard et al, 2009; Shaw et al, 2008; Biggio et al, 2010

Blomberg & Kallen, 2010

Obesity and Anomalies

BMI ≥30NTD 2.04 (1.5-2.7)Cardiac 1.17 (1.1-2.2)Cleft 1.26 (1.1-2.0)Anal atresia 1.87 (1.4-2.5)Cystic kidney 1.40 (1.0-1.9)Omphalocele 2.03 (1.4-2.9)

BMI 30-34.9 35-39.9 ≥40

NTD 1.8 (1.3-2.5) 2.1 (1.1-3.5) 4.1 (1.9-7.8)

Cardiac 1.1 (1.0-1.2) 1.3 (1.1-1.4) 1.5(1.2-1.8)

Cleft 1.1 (0.9-1.3) 1.6 (1.3-2.1) 1.9 (1.3-2.9)

Anal atresia 1.8 (1.3-2.4) 1.5 (0.7-2.6) 3.7 (1.7-7.1)

Dose-Dependent

Blomberg & Kallen, 2010

Perinatal Mortality

0

1

2

3

4

5

Adju

sted

OR*

Cedergren – Obstet Gynecol 2004

19.8 – 26.0 29.1 – 35.0 35.1 – 40.0

BMI (kg/m2)

> 40.0

Stillbirth after 28 weeksEarly Neonatal Death

Perinatal Complications

• Preeclampsia

• Preterm birth

• Gestational diabetes

• Fetal macrosomia

• Fetal Demise

Pre-eclampsia

0

1

2

3

4

5

Adju

sted

OR*

Cedergren – Obstet Gynecol 2004

19.8 – 26.0 29.1 – 35.0 35.1 – 40.0

BMI (kg/m2)

> 40.0

Pre-eclampsia

• Each BMI unit increases risk 0.5%• Normal weight 2-4%• BMI ≥ 30 8-12%

• Similar magnitude regardless of race

Bodnar et al, Epidemiology, 2007

O’Brien et al, Epidemiology, 2003

Preterm Birth

• Conflicting literature• Multiple studies suggest protective against SPTB• Obesity characterized by inflammation

• Large meta-analysis of overweight and obese women• PTB <37 wk RR 1.06 (0.87 – 1.3)• SPTB RR 0.93 (0.85 – 1.01)• Indicated PTB RR 1.30 (1.23 – 1.37)

McDonald et al, 2010

Preterm Birth

• Swedish Birth Registry• SPTB

• Extremely PTB (22-27 wk) increases with BMI

• No increase in 28-31 or 32-36 wk

• Indicated PTB• Increased for all GA and all BMI >25• Highest risk BMI ≥40

BMI 25-<30 30-<35 35-<40 ≥401.12 (1.0-1.2) 1.22 (1.04-1.44) 1.73 (1.35-2.21) 2.71 (1.95-3.78)

Cnattingius et al, 2013

Gestational Diabetes

0

1

2

3

4

Odd

s Ra

tio

Sebire 2001

20 - 24.9 25 – 29.9

BMI (kg/m2)

>30

LGA/Macrosomia

0

1

2

3

4

Odd

s Ra

tio

Cedergren, Obstet Gynecol, 2004

29.1 – 35 35.1 – 40

BMI (kg/m2)

>40

• Mechanism unclear• Meta-analysis

• Overweight 1.5 (1.1 – 1.9)• Obese 2.1 (1.6 – 2.7)

• Translate to 1.4% SB rate

• Ethnic disparity in risk• Caucasian 1.4 (1.3 – 1.5)• AA 1.9 (1.7 – 2.1)

Chu et al, 2007

Salihu et al, 2007

Fetal Demise

Fetal Demise

• Stillbirth Collaborative Network• Obesity/overweight independently associated • aOR 1.72 (1.22 – 2.43)

• Danish Birth Cohort• 28-36 wk HR 2.1 (1.0 – 4.4)• 37-39 wk HR 3.5 (1.9 – 6.4)• ≥40 wk HR 4.6 (1.6 –

1.3)Stillbirth Network, 2011; Nohr et al,

2005

Peripartum Complications

• Labor induction

• Cesarean delivery

• Labor dysfunction

• Postpartum hemorrhage

• Shoulder dystocia

• Wound complications

• Neonatal complications

Induction of Labor

BMI 29.1-35 BMI 35.1-40 BMI > 400

0.5

1

1.5

2

2.5

Cedergren, Obstet Gyncecol, 2004

Odd

s ra

tio

Cesarean Delivery

BMI 29.1-35 BMI 35.1-40 BMI > 400

0.5

1

1.5

2

2.5

3

Cedergren, Obstet Gyncecol, 2004

Odd

s ra

tio

Cesarean: Wound Infections

0

1

2

3

4

5

100 – 199 lb 200 – 299 lb ≥ 300 lb< 100 lb

% W

omen

with

Wou

nd In

fecti

ons

NICHD MFMU C/S Registry 2002

p < 0.0001

C/S Contributors

• Inductions• Co-morbidities• Presumed macrosomia

• Fetal decompensation intrapartum• Dysfunctional labor

• 3.5X rate of CS in first stage of labor• Increased need for augmentation and higher

doses of oxytocin• In vitro—poor myometrial contractility

Zhang et al, BJOG, 2007

Postpartum Hemorrhage

BMI 29.1-35 BMI 35.1-40 BMI > 400

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Cedergren, Obstet Gyncecol, 2004

Odd

s ra

tio

Anesthesia risks

• Failed intubation 4-6x• Soft tissue mass

• Ventilation difficulties• Breast mass

• Decreased lung volumes

• Failed /difficult regional

Juvin et al, Anesth Analges, 2003; Jordan et al, AJOG, 2004

Long-term Risks

• Increasing maternal obesity• Co-morbidities

• Developmental origins of obesity• Childhood obesity• Metabolic syndrome

Post-Partum Weight Retention

• Gestational weight gain retention• Mean 11.8 lb at 6 months• GWG > IOM

• 15 – 20 lb retention• >40% of women with >20 lb retention

• >50% overweight women are obese by 1 yr postpartum

IOM, 2009; Gould Rothberg, AJOG, 2011

Breastfeeding

• Obese women less likely to breastfeed• BMI 25-30 0.86 (0.84 – 0.88)• BMI >30 0.58 (0.56 –

0.60)

• Missed potential benefits• Maternal

• InfantSebire et al, Intl J Obesity, 2001; Li et al, Am J Pub Health, 2002

Childhood Obesity

• Maternal obesity correlates with neonatal fat mass

• Obesity in offspring of obese mothers• BMI >95th percentile at ages 2-4• OR 2.4 – 2.7

• ↑ Central obesity, lipid abnormalities, hypertension–age 7

Whitaker RC, Pediatrics, 2004; Oken et al, AJOG, 2007;Catalano et al, AJOG 2003, 2004

Summary of Problem

• Scope of the problem is far-reaching• Pregnancy• Life-long• Next generation

Optimizing Perinatal Outcomes

Initial Antepartum Evaluation

• Assessment for co-morbidities• Metabolic syndrome:

• Hypertension

• Glucose intolerance/Diabetes

• Hyperlipidemia

• Sleep apnea

• Early dating US• Oligo-ovulation LMP unreliable

Optimizing Outcomes: Gestational Weight Gain

• Education• Dietary Intake• Exercise

• Set goals and plot weight gain • Only ~250 kcal/d increase needed for

normal weight

Optimizing Outcomes: Gestational Weight Gain

• Total Weight Gain• 11-20 lb• 0.5 lb/wk in 2nd & 3rd trimesters

• Nearly 2/3 of obese women exceed recommended GWG

Gestational Weight Gain

• Excess weight gain associated with• Macrosomia• Operative delivery• NICU

• Weight gain <15 lb associated with lower rates of:• Pre-eclampsia• Cesarean• LGA/SGA

Kiel et al, 2007

Pre-E: Effect of Weight Gain

• Overweight and Obese women

• Weight gain

<15 lb OR 0.5 – 1

> 25 lb OR 1.2 – 1.7

Kiel et al, 2007

Optimizing Outcomes: Early GDM Screening

• Lack of evidence of cost-effectiveness• Target population

• Previous history GDM• Family history of DM• Prior macrosomic infant

• Treatment may lower risks • HgbA1C and risk assessment for other

complicationsCatalano, 2007

Optimizing Outcomes: Reducing pre-eclampsia

• Patients with GDM—Improved glycemic control, lower risk pre-e• ACHOIS—18% vs 12%• MFMU—13.6 % vs 8.6%

Landon et al, 2009; Crowther et al, 2005

Optimizing Outcomes: OSA

• CPAP• Improves symptoms, mood• BP, pre-eclampsia• Birthweight

• Minimize use of narcotic pain relief• Anesthesia consultation• If not confirmed, monitor O2 sats

• Sleep Medicine referralFranklin et al, 2000; Poyares et al,

2007; Guilleminault et al, 2007

Anatomic Assessment

• U/S Visualization• Completion of anatomic assessment declines with increasing

BMI

• 10% decrement per obesity class

Dashe et al, 2009; Thornburg et al, 2009; Weichert and Hartge, 2010; Hendler et al, 2004; Becker and Wegner, 2006

<25 25-29.9 30-34.9 35-39.9 ≥40Basic 72% 68% 57% 41% 30%Targeted 97% 91% 75% 88% 75%

Dashe et al, 2009; Aagaard et al, 2010

• Detection rate decreases with increasing BMI

• Residual anomaly risk increases with BMI

FASTER Trial• Detection aOR 0.70

(0.6-0.9)

Optimizing Outcomes: Anatomic Assessment

• 11-14 week scan• Lack of evidence in obese women

• Combined TA and TV approach• 82% complete anatomy• 3.7% anomaly detection• 84.2% heart defect detection

Ebrashy et al, 2010; Becker and Wegner, 2006

Optimizing Outcomes: Prenatal Diagnosis

• NIPT• Fetal fraction lower

• Adipose cell death• Inflammation

• Redraw rates• Diagnostic Procedures

• BMI ≥40 2-fold increase loss after amnio

Ashoor et al, 2013; Haghiac et al, 2012; Harper et al, 2012

Fetal Fraction in Relation to BMI

Ashoor et al, 2013

Optimizing Outcomes: Growth Surveillance• Macrosomia

• 2-fold increase

• IUGR• Mainly in women with hypertension or pre-eclampsia

• Fundal height• Limited accuracy

• Biometry q4-6 weeks

Ehrenberg et al, 2004; Neilson, 2000; Morse et al, 2009; ACOG CO

#549, 2013

Optimizing Outcomes: Antenatal Testing

• Placental histology • Placental dysfunction OR 5.2

• Vigilance for hypertension, diabetes

• Antenatal surveillance • Even in absence of other indications

Catalano, 2007; Nohr et al, 2005

Optimizing Outcomes: Mode of Delivery• Labor dysfunction

• Increased oxytocin dose• 5.0 units vs 2.6 units

• Longer labor duration• 8.5 vs 6.5 hours

• Impaired myometrial contractility• Leptin inhibitory effect• Not oxytocin receptor mediated

Pevzner et al, 2009; Quenby wt al, 2011; Zhang et al, 2007, 2011; Moynihan et al, 2006; Grotegut et al, 2013

Vaginal vs Cesarean• Swedish birth registry• Neonatal outcomes by mode of delivery• 2-4 fold increase for BMI ≥40 :

• Birth injury• RDS• Sepsis• Hypoglycemia

• Similar risk vaginal vs. elective cesarean

Blomberg, 2013

Optimizing Outcomes: Mode of Delivery• Lack of evidence• Factors to consider

• Increased need for cesarean

• Ability to monitor fetal status

• Time from skin to delivery increased

Gunatilake and Perlow, 2011

VBAC Success

• MFMU Cesarean Registry• >14,000 VBAC attempts

Hibbard et al, 2006

18.5-24.9 25.0-29.9 30-39.9 ≥40 pFailed TOL 15.2 22.3 29.9 39.3 <0.001LOS ≥4d 9.4 13.0 18.9 30.3 <0.001Endometritis 1.6 2.6 3.0 4.6 <0.001Rupture/dehiscence

0.9 1.5 1.4 2.1 0.03

• Reduces risk of puerperal fever• Endomyometritis• Wound infection

• Weight-based dosing modification• Cefazolin

• ≤80 kg 1 gm• 81-160 kg 2 gm• ≥160 kg 3 gm

Perioperative Antibiotics

JCAHO, SCIP recommendations; Smaill et al, 2010;

Cefazolin in obese

• 29 scheduled C/S; 2 gm cefazolin

• Adipose concentration inversely related to BMI• BMI ≥30 20% less than MIC for GNR• BMI ≥40 up to 44% less than MIC

Pevzner et al, 2011

Optimizing Outcomes: Intraoperative management

• Incision type• Fascial Closure• Subcutaneous closure• Appropriate Equipment

• Bed• Instruments• Transfer apparatus

Incision Type and Placement• Pfannenstiel

– Less adipose depth

– Access to LUS– More stable

closure– Moist, anaerobic,

microbe-rich– Cava

compression– Respiratory

impairment intraop

• Vertical• Avoid under pannus• More room• Cut through thicker

part of panniculus• Placement difficult• Increased likelihood

of vertical hysterotomy

• Pulmonary issues post

• Less stable closureWall et al,2003; Alanis et al, 2010; Bell et al, 2011

• 194 women BMI >50• 30% wound complication• Vertical incision OR 2.2 (1.2 – 4.3)

• 239 women BMI > 35• 12% wound complication• Vertical incision OR 12.4 (3.9 – 39.3)

Pfannenstiel vs Vertical

Alanis et al, AJOG, 2010; Wall et al, Obstet Gynecol, 2003

Optimizing Outcomes: Subcutaneous Space Management

• Meta-analysis• Depth >2 cm• Wound disruption RR 0.66 (0.48-0.91)

• Reduction in wound seroma RR 0.42

• No added benefit to drain

Chelmow et al, 2004; Magann et al, 2002; Ramsey et al, 2005

Optimizing Outcomes: Intrapartum management

• Minimize induction of labor, as possible• Anticipate longer length of labor and need for higher

doses of oxytocin• Early epidural placement for analgesia• Decision on best mode of delivery

• Fetal monitoring capability• Prior C/S• EFW

Optimizing Outcomes: Intrapartum management

• Prophylactic cesarean considered for macrsomia• Prepare for pp hemorrhage regardless of mode of

delivery• Choose surgical approach and instruments to

facilitate exposure and technique

ACOG Practice Bulletin 22, 2000

Optimizing Outcomes: Thromboprophylaxis

• Obesity major risk factor• OR 4.4 (3.4 – 5.7) for VTE

• No RCT with benefit of UFH vs LMWH vs pneumatic compression device• At least one form recommended

• High risk patients--heparin plus pneumatic• Vascular disease, thrombophilia, severe pre-e

• Early ambulation

James et al, 2006; Bates et al, 2008; Tooher et al, 2010

• Obesity is associated with an increased risk of a number of maternal obstetric and medical complications

• Good evidence is available to minimize the risk of many complications associated with obesity

• Although data are lacking on how to prevent a number of these complications, careful preparation and anticipation may minimize the risks and improve outcomes in the current and future pregnancies

Summary