nutrition 526 - 9/29/2006 a public health approach to maternal and infant health

Nutrition 526 - 9/29/2006

A Public Health Approach to Maternal and Infant Health

Topics

1. Who is having babies in the US? How many babies? What are the outcomes?

2. Why is nutrition important for pregnant women and babies?

3. What population based approaches to improve nutrition might improve outcomes?

Topic 1

• How many babies? • Who is having babies in the US?

– Race/ethnicity– Age – Marital status

• What are the nutrition-related outcomes we are concerned about for population health?

Health, United States, 2005: www.cdc.gov/nchs/hus.htm

Percentage of Parents Who Were Married or Cohabiting at Birth of First Child, by Race/Ethnicity and Sex

MMWR; September 15, 2006 / 55(36);998

Infant Mortality

• Infant mortality rate – Deaths of infants aged under 1 year per 1,000 or 100,000 live births. The infant mortality rate is the sum of the neonatal and postneonatal mortality rates.

• Neonatal mortality rate – Deaths of infants aged 0-27 days per 1,000 live births. The neonatal mortality rate is the sum of the early neonatal and late neonatal mortality rates

• Postneonatal mortality rate – Deaths to infants aged 28 days-1 year per 1,000 live births.

http://www.chipublib.org/004chicago/disasters/infant_mortality.html

Infant Deaths Per Thousand Live Births, by Race and Hispanic Origin 1960-1995

National Center for Health Statistics. Health, United States, 1995

Racial/Ethnic Disparities in Infant Mortality --- United States, 1995--2002

MMWR; June 10, 2005 / 54(22);553-556

MMWR, April 19, 2002 / 51(15);329-332, 343

Figure 2. Rates of infant mortality, low birthweight, and preterm birth, 1990-2002

Supplemental Analyses of Recent Trends in Infant Mortality, CDC February 11, 2004

Health Affairs, Vol 23, Issue 5, 2004

Causes of Infant Death

Health Affairs, Vol 23, Issue 5, 2004

Rates of LBW (%)

Rates of Premature Birth (%)

Rates Infant Morality(%)

African Americans

13.4 17.7 13.5

Asians 7.8 10.4 4.6

Native Americans

7.2 13 9.7

Whites 6.9 11 5.7

Hispanics 6.5 11.6 5.4

NGA Center for Best Practices, June 2004

Reported Stressful Life Events During Year Before

Delivery

King County, 1999-2001Pregnancy Risk Assessment Monitoring

System (PRAMS)

African Amer.

Amer. Indian/AK Native

White

Changed residence 44%* 53%* 33%

Argued with partner more than usual 36%* 43%* 17%

Had bills couldn’t pay 31%* 42%* 14%

Someone close died 24%* 25% 15%

Close family member hospitalized 24% 22% 24%

Separated or divorced from partner 20%* 19%* 5%

Someone close had drinking/drug problem 15% 28%* 13%

Partner said he didn’t want pregnancy 15%* 21%* 8%

Husband/partner lost job 14% 20%* 8%

Mom or partner went to jail 10% 22%* 4%

Involved in a physical fight 7% 12%* 4%

Homeless 11%* 15%* 1%

Reported 5 or more stress events 12%* 23%* 4%

* stat. sig compared to whites

Maternal Mortality

African American and White Women Who Died of Pregnancy Complications,* United States

* Annual number of deaths during pregnancy or within 42 days after delivery, per 100,000 live births. † The apparent increase in the number of maternal deaths between 1998 and 1999 is the result of changes in how maternal deaths are classified and coded. Source: CDC, National Center for Health Statistics.

Risk of Maternal Death

• Race/ethnicity– The risk of death for African American women is

almost four times that for white women. – The risk of death for Asian and Pacific Islander

women who immigrated to the United States is two times that for Asian and Pacific Islander women born in the United States.

• Age– The risk of death is nearly three times greater for

women 35–39 years old than for women 20–24 years old.

– The risk is five times greater for women over 40.

The most common serious pregnancy complications

• Ectopic pregnancy • Depression• High blood pressure • Infection • Complicated delivery • Diabetes• Premature labor • Hemorrhage

Topic 2

• Why is nutrition important for pregnant women and babies?

Poor Pregnancy Outcomes are Costly

• Medicaid finances 40% of annual births in the US and pays for 50% of hospital stays for premature and LBW.

• The care cost for children with one of 17 common birth defects is $8 billion per year in the US.

Top Three “Best Practices” to Improve Birth Outcomes and Reduce High Risk Births

(NGA, June 2004)

• Improve access to medical care and health care services

• Encourage good nutrition and healthy lifestyles– Eating healthy foods– Taking folic acid

• Reduce use of harmful substances

Emerging Understandings about Nutrition in Pregnancy:

• Fetal nutritional status is affected by the intrauterine and childhood nutritional experiences of the mother

• Maternal nutritional status at time of conception is an important determinant of outcomes

• Intrauterine nutritional environment affects health and development of the fetus throughout life

Emerging Understandings about Nutrition in Pregnancy

• Periods of critical development are key when considering effects of nutrition in pregnancy.

• Undernutrition has different effects at different times of life.

• Societies transitioning from chronic malnutrition to access to high calorie foods are at high risk of chronic disease due to lasting effects of early nutritional status.

Effect of Women’s own Intrauterine Nutritional

Experience her Offspring

Two Studies of Effects of Maternal Birthweight on Infant

Birthweight

Classic Definitions of Birth weightExtremely low birth weight (ELBW) < 1000 g

Very low birth weight (VLBW) <1500 g

Moderately Low birth weight 1500 to <2500 g

Low birth weight <2500 g (HP2010)

Normal (NBW) 2500-<4000 g

Ideal birth weight 3500- <4000g

High birth weight (HBW) >4000 g

Godfrey KM, Barker DJP, Robinson S, Osmond C. Mother's birthweight and diet in pregnancy in relation to the baby's thinness at birth. Br J Obstet Gynaecol 1997;104:663–7

Illinois StudyCoutinho et al. Am J Epi, 1997 146:804-809

• N=15,287 Black and 117,708 white matched pairs of infants and mothers.

• Mothers were born between 1956-75, infants between 1989-1991

Black White

Mean infant birthweight 3139 g 3434

Mean parental birthweight 3133 3377

% low birthweight infants 12% 5%

% lbw born to women with lbw 18% 9%

% lbw born to women not lbw 11% 5%

Results

• Father’s birthweight had effect on infant birthweight but not as strong as mothers.

• In multiple linear regression for infants who weighed more than 2500 g, parental birthweight accounted for 5% of variance among black infants and 4% among white infants.

• (adjusted for parental age, years of schooling, marital status and adequacy of prenatal care)

Results, cont.

• Each 100 g increase in maternal birthweight was associated with 24-27 g increase in infant birthweight

Influence of Maternal Intrauterine & Childhood Nutrition on Outcomes of

Pregnancy

Reproductive performance and nutrition during childhood

Nutrition Reviews; Washington; Apr 1996; Martorell, Reynaldo; Ramakrishnan, Usha; Schroeder, Dirk G; Ruel, Marie;

Longitudinal Supplementation Trial (1969-1977)

• Guatemala, 4 Villages, one pair of villages had about 900 people each and the other about 500 each.

• 2 each randomized to:• Atole (Incaparina, a vegetable protein mix

developed by INCAP*, dry skim milk, sugar, and flavoring, 163 kcal/cup, 11/5 g protein)

• Fresco (flavored drink with sugar, vitamins and minerals, 59 kcal/cup)

*Institute of Nutrition of Central America and Panama

• Feeding center was open daily for over 7 years, from 1969 to 1977.

• Anyone in the village could attend, but careful recording of consumption, including of additional servings as well as of leftovers, was done only for women who were pregnant or breastfeeding and for children 7 years or younger.

• Supplements were available twice daily, in midmorning and midafternoon, so as not to interfere with meal times.

Conceptual framework

“Malnutrition in early childhood constrains the future capacity of women to bear healthy newborns and their ability to feed and care for them, and through these mechanisms the growth and development of the next generation.”

Follow-Up data - 1990s

• The prevalence of low birthweight is currently 12% in Atole villages (n = 65) and 28% in Fresco villages (n = 58) among women exposed to the supplements during the intrauterine period and the first 3 years of life.

• Mean birthweights are 2.90 kg in Atole villages and 2.73 in Fresco villages.

Role of intergenerational effects on linear growth

U Ramakrishnan; R Martorell; D G

Schroeder; R Flores; The Journal of Nutrition; Bethesda; Feb 1999;

Methods

• The sample was restricted to singleton, term (>37 wk of gestation) births that occurred in the four study villages between 1991 and 1996, to women who were born during the original longitudinal study (1969-1977)

• Complete data were available for 215 mother-child pairs, and 60% of the mothers (n = 140)

Results

• For every 100 g increase in maternal birth weight, her infant's birth weight increased by 29 g after adjusting for the effects of maternal age, gestational age and sex of the infant. This relationship was highly significant (P < 0.001)

• For every centimeter increase in maternal birth length, her child's birth weight increased by 53 g.

Influence of Maternal Nutrition in Pregnancy

Dutch Famine StudiesSusser and Stein, Nutrition Reviews, 1994

• Dutch famine winter lasted 6 months, from November 1944- when nazis imposed transport embargo on west Holland until-

• May 7, 1945 when Holland was liberated from the occupation

• Strong evidence for critical stages of development in several physiological systems

Affects of Famine

• Fertility decreased• Maternal weight fell during pregnancy

with famine exposure• Third trimester famine exposure had

strong effect on birthweight• Third trimester famine exposure was

associated with infant mortality at 30-90 days

Results for Infants Exposed to Famine

• Excess central nervous system disorders (such as NTD)

• Exposure early in gestation associated with excess obesity in young men (military records) and women

• Famine exposure late in pregancy associated with less obesity in young adulthood

• Famine exposure associated with twofold risk of schizophrenia in 50 year old women.

Second Generation

• Modest association found in this cohort between birthweights of mothers and their offspring.

Prenatal exposure to famine and brain morphology in schizophrenia

Hulshoff Pol HE; Hoek HW; Susser E; Brown AS; Dingemans A; Schnack HG; van Haren NE; Pereira Ramos LM; Gispen-de Wied CC; Kahn RS; American Journal of Psychiatry , Jul 2000;

Methods

• Nine schizophrenic patients and nine healthy comparison subjects exposed during the first trimester of gestation to the Dutch Hunger Winter were evaluated with magnetic resonance brain imaging, as were nine schizophrenic patients and nine healthy subjects who were not prenatally exposed to the famine.

RESULTS:

• Prenatal famine exposure in patients with schizophrenia was associated with decreased intracranial volume.

• Prenatal Hunger Winter exposure alone was related to an increase in brain abnormalities, predominantly white matter hyperintensities.

Further evidence of relation between prenatal famine and

major affective disorder.

Alan S Brown; Jim van Os; Corine Driessens; Hans W Hoek;

et al; The American Journal of Psychiatry; Washington; Feb

2000;

Methods

• Compared the risk of major affective disorder requiring hospitalization in birth cohorts who were and were not exposed, in each trimester of gestation, to famine during the Dutch Hunger Winter of 1944-1945.

Results

• The risk of developing major affective disorder requiring hospitalization was increased for subjects with exposure to famine in the second trimester and was increased significantly for subjects with exposure in the third trimester, relative to unexposed subjects.

Fetal Nutrition and Chronic Diseases of Adulthood

Fetal Origins ConceptsBarker et al

• Nutrition in early life has permanent effects on structure, physiology and metabolism

• Undernutrition has different effects at different times of life (critical periods of development)

• Rapidly growing fetuses and neonates are vulnerable to undernutrition

• Undernutrition results from inadequate maternal intake, transport, or transfer of nutrients.

Coronary heart disease death rates, expressed as standardized mortality ratios, in 10,141 men and 5585 women born in Hertfordshire, United Kingdom, from 1911 to 1930, according to birth weight.

(Osmond C, Barker DJP, Winter PD, Fall CHD, Simmonds SJ. Early growth and death from cardiovascular disease in women. BMJ 1993;307:1519–24)

Catch-up growth in childhood and death from coronary heart disease: longitudinal

study (Eriksson et al, BMJ, 1999)

• Subjects: 3641 men born in Helsinki between 1924-1933

• Followed with school data for weight and height

• Deaths from coronary heart disease from 1971-95 (standardized mortality ratios) were endpoints.

Catch-up growth in childhood and death from coronary heart disease: longitudinalstudy (Eriksson et al, BMJ, 1999

• Men who had low birth weight or were thin at birth have high death rates from coronary heart disease

• Death rates are even higher if weight "catches up" in early childhood

• Death from coronary heart disease may be a consequence of prenatal undernutrition followed by improved postnatal nutrition

• Programs to reduce obesity among boys may need to focus on those who had low birth weight or who were thin at birth

Framework for understanding the maternal regulation of fetal development and programming. Keith M Godfrey and David JP Barker

(Fetal nutrition and adult disease Am J Clin Nutr 2000 71: 1344-1352)

Early Nutrition & Chronic Disease in

Adulthood (Waterland& Garza, Am J Clin Nutr, 1999;69:179-97)

• Epi studies: BMI, CVD, Htn, IGT

• Animal studies

• Potential mechanisms of metabolic imprinting

Obesity in Young Men after Famine Exposure in Utero and early Infancy(Ravelli et al NEJM, 1976)• N=300, 000 Dutch military inductees at age 19

• Famine exposure in first 2 trimesters lead to 80% higher prevalence of overweight (p<0.0005)

• Famine exposure in last trimester or famine exposure in first 5 months of life associated with 40% lower prevalence of overweight (p<0.005)

BMI

• The relationship between birth weight and BMI complicates studies of birth weight and chronic disease

Preadult Influences on Cardiovascular Disease and Cancer (Leon & Ben-Shlomo in A Lifecourse approach to

chronic disease epidemiology, 1997)

• 5 large retrospective studies - 4 found inverse relationship between birth weight and adult CVD

• Confounding issues include SES and BMI

CVD

“The preponderance of data suggest an inverse association between birth weight and adult CVD risk.” (Waterland and Garza)

Blood Pressure

“Retrospective studies in diverse populations have found that birth weight is inversely correlated with adult blood pressure. Although each of the studies has some weaknesses, together they support a biological link between intrauterine growth and adult blood pressure” (Waterland and Garza)

Impaired Glucose Tolerance

• Several large retrospective cohort studies in several countries have found relationship between bw and IGT.

• 266 men and women at age 50: odds ratio for ITG or type II diabetes were 3.5 for men and 12 for women with birth weights < 2.5 compared to >3.4 (Phillips et al, Diabetologia, 1994)

Impaired Glucose Tolerance, cont..

• In some populations (ex: Pima Indians) both high and low birth weights are associated with IGT in adults.

Animal Models (Waterland and Garza)

“Overall the data from animal models of metabolic imprinting support the observed epidemiological associations.”

Epigenetics• Epigenetics = the study of stable alterations in gene

expression that arise during development and cell proliferation Epigenetic phenomena do NOT change the actual, primary genetic sequence

• Epigenetic phenomena are important because, together with promotor sequences and transcription factors, they modulate when and at what level genes are expressed

• The protein context of a cell can be understood as an epigenetic phenomena.

• Examples include: DNA methylation, histone hypo-acetylation, chromatin modifications, X-inactivation, and imprinting.

http://cnx.rice.edu/content/m11532/latest/

Metabolic Imprinting

“…the basic biological phenomena that putatively underlie relations among nutritional experiences of early life and later diseases.”

Metabolic Imprinting: Characteristics

• Susceptibility limited to a critical ontogenic window early in development

• Persistent effect lasting through adulthood

• Specific and measurable outcome

• Dose-response or threshold relation between exposure and outcome

Metabolic Imprinting: Potential Mechanisms

• Organ structure

• Cell number & function

• Clonal selection

• Metabolic differentiation

Organ Structure

• Organogenesis starts early: by 5 weeks rudimentary organs are in place, by 8 weeks organogenesis is nearly complete

• Driven by inductive signals from adjacent cells and morphogen gradients (ex: retinoic acid/vit. A)

• Local concentrations of nutrients and metabolites may modulate this process.

Cell Number

• Tissues go through limited periods of hyperplastic and hypertrophic growth

• Rate of growth is dependent on nutrient availability

• Winnick’s rat studies found severe malnutrition during critical periods limited brain cell number

• An organ’s metabolic activity is limited by cell number

Cell Function:

• Early nutrition may influence the cascade that establishes cell specific patterns.

• Ex: hepatocyte polyploidization - in adults hepatocytes often have > normal complement of chromosomes and increased metabolic activity. Lack of polyploidization could limit hepatic metabolic activity.

Clonal Selection

• Each organ is based on a finite number of founder cells which may have slight differences

• Founder cells that divide the most rapidly may disproportionally make up a tissue

• Nutrient availability may “select” cells with certain characteristics

• Ex: cells with more active lipogenic pathways could grow faster if access to fatty acids was limited

Metabolic Differentiation

• Process: cells develop stable patterns of basal and inducible gene expression

• Cells are characterized by the ability to express a limited number of genes.

• Mechanisms of control include:– chromatin structure (DNA “packaging”)– transcription factors (maintained through cell

divisions)– DNA methylation

Fall et al, 1988

Gluckman et al. Biology of the Neonate, 2005

• Public Health Approaches to Nutrition and Pregnancy – Assessment– Policy Development– Assurance

Topic 3

Assessment

• Planning for Pregnancy

• Risk Behaviors

Effects of pregnancy planning status on birth outcomes and infant care (Kost

et al. Family Planning Perspectives, 1998)

• Analysis of 1988 NMIHS (n=9122) and NSFG (n=2548) data.



Intended Mistimed Unwanted

LBW 5.1 6.5 9.7

SGA 9.5 11.3 13.7

Anynegativeoutcomes

15.6 20.4 25.5

Everbreastfed

59.9 46.6 36.1



• “Knowing the planning status of a pregnancy can help identify women who may need support to engage in prenatal behaviors that are associated with healthy outcomes and appropriate infant care.”

Surveillance for Pregnancy

• PRAMS results – Washington State

Alcohol

MMWR, December 24, 2004

Multivitamin Use

Breastfeeding Duration

Smoking

Unintended Pregnancy

Post-Partum Depression – PRAMS

Washington State PRAMS

WA State PRAMS

Key Indicators of Perinatal Health for Washington Residents: August 2005

•The total number of live births has remained stable since 1998 at approximately 80,000 births per year.•Medicaid-funded deliveries represented 45.6% of births in 2003.•Birth rates and pregnancy rates decreased among teens 15-17 years and 18-19 years, especially from 1993 to 2003.•Since the mid-1990s, total infant mortality, race-specific infant mortality and Medicaid-specific infant mortality have decreased slightly.

Indicators, cont.

•SIDS rates have decreased substantially since 1990, however changing reporting practices of coroners/medical examiners have played a role in this decline.•Smoking during pregnancy, as reported on the birth certificate, has declined since 1992.•In 2002, the percent of women initiating breastfeeding was high in Washington State at approximately 90%.

Areas of Concern in WA State

•Total low birth weight has increased steadily since 1990, in part due to the increase in multiple deliveries.•In 2003, African American and Native American infant mortality rates continued to exceed infant mortality rates of other race and ethnic groups.•In 2003, the highest singleton low birth weight (LBW) rate was for African Americans.

Key Indicators of Perinatal Health for Washington Residents: August 2005

Concerns, cont.•The singleton VLBW rate among African Americans remained over twice the rate of Whites between 1990 and 2003.•In 2003, women receiving Medicaid had lower rates of first trimester prenatal care and higher rates of late and no prenatal care than women who did not receive Medicaid.•In 2003, smoking rates during pregnancy were significantly higher for women receiving Medicaid than for women who did not receive Medicaid.•In 2002, the unintended pregnancy rate was approximately 54%.

Healthy People 2010 Goals Related to Maternal and Infant

& Nutrition

Reduce low birth weight (LBW) and very low birth weight (VLBW).

1998Baseline

2010TargetReduction in Low and

Very Low Birth Weight Percent

Low birth weight (LBW) 7.6 5.0Very low birth weight(VLBW)

1.4 0.9

Reduce preterm births

Reduction inPreterm Births

1997Baseline (%)

2010Target (%)

Total preterm 11.4 7.6

Live births at 32 to 36weeks of gestation

9.4 6.4

Live births at lessthan 32 weeks ofgestation

1.9 1.1

Reduce the occurrence of spina bifida and other neural tube defects (NTDs)

• Target: 3 new cases per 10,000 live births.

• Baseline: 6 new cases of spina bifida or another NTD per 10,000 live births in 1996.

Increase the proportion of pregnancies begun with an optimum folic acid level.

Increase in PregnanciesBegun With OptimumFolic Acid Level

1991–94Baseline*

2010Target

Consumption of at least400 μg of folic acid eachday from fortified foods ordietary supplements bynonpregnant women aged15 to 44 years

21% 80%

Median RBC folate levelamong nonpregnantwomen aged 15 to 44years

161 ng/ml 220 ng/ml

Increase abstinence from alcohol, cigarettes, and illicit drugs among pregnant women

Increase in ReportedAbstinence in PastMonth FromSubstances byPregnant Women*

1996–97Baseline %

2010Target %

Alcohol 86 94

Binge drinking 99 100

Cigarette smoking† 87 98

Illicit drugs 98 100

Increase the proportion of mothers who breastfeed their babies

Increase in MothersWho Breastfeed

1998Baseline (%)

2010Target (%)

In early postpartumperiod

64 75

At 6 months 29 50

At 1 year 16 25

Increase smoking cessation during pregnancy

• Target: 30 percent.

• Baseline: 12 percent smoking cessation during the first trimester of pregnancy in 1991 (age adjusted to the year 2000 standard population).

Reduce growth retardation among low income children under age 5 years


• Baseline: 8 percent of low-income children under age 5 years were growth retarded in 1997 (defined as height-for-age below the fifth percentile in the age-gender appropriate population using the 1977 NCHS/CDC growth charts;31 preliminary data; not age adjusted).

Reduce iron deficiency among young children and females of childbearing age.

Reduction in IronDeficiency*

1988–94Baseline (%)

2010Target (%)

Children aged 1 to 2years

9 5

Children aged 3 to 4years

4 1

Nonpregnant femalesaged 12 to 49 years

11 7

Reduce anemia among low-income pregnant females in their third trimester


• Baseline: 29 percent of low-income pregnant females in their third trimester were anemic (defined as hemoglobin < 11.0 g/dL) in 1996

Anemia Rates - 1996

African American, non-Hispanic 44%

American Indian/Alaska Native 31%

Asian/Pacific Islander 26%

Hispanic 25%

White, non-Hispanic 24%

nutrition 526 - 9/29/2006 a public health approach to maternal and infant health

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