Energy and Weight Gain in Pregnancy

1. Energy and Weight Gain in Pregnancy 2012

2. Energy Requirements in Pregnancy • Increased energy costs in pregnancy: • increased maternal metabolic rate • fetal tissues • increase in maternal tissues

3. DRI for Energy in Pregnancy - 2002

4. Estimated Energy Requirement • Average dietary energy intake that is predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height, level of physical activity consistent with good health. • In children, pregnant and lactating women the EER is taken to include the needs associated with deposition of tissues or secretion of milk

6. BEE: Basal Energy Expenditure • BEE = energy consumed while at rest and fasting • In pregnancy BEE increases due to metabolic contribution of uterus and fetus and increased work of heart and lungs. • Variable for individuals

8. Growth of Maternal and Fetal Tissues • Calculations Based on: • Hytten • IOM weight gain recommendations

10. T1 and T2 ~ 180 kcal per day

12. Longitudinal Data from DLW Database • Median TEE (total energy expenditure) change from non-pregnant was 8 kcal/gestational week. • TEE changes little in first trimester.

15. Variations in Energy Requirements • Body size - especially lbm • Activity: • most women decrease activity in last months of pregnancy if they can • increased energy cost of moving heavier body • BMR • rises in well nourished women (27%) • rises less or not at all in women who are not well nourished • -Diet Induced Thermogenesis?

16. Evidence of energy sparing in Gambian women during pregnancy: a longitudinal study using whole-body calorimetry (AJCN, 1993) • N=58, initially recruited, ages 18-40 • 25 became pregnant • 21 participated in study protocols • 9 completed BMR and 24 hour energy expenditure • 12 completed BMR • Adjusted for seasonality, weight loss expected during wet season

17. Poppitt et al., cont. • Mean maternal prepregnancy weight was 52 kg • Mean prepregnancy BMI was 21.2 + 2 • Mean birthweight was 3.0 + 0.1 • Mean gestational length was 39.4 • Mean weight gain was 6.8 kg • Mean fat gain was 2.0 kg at 36 weeks

18. Poppitt et al., cont. • BMR fell in early pregnancy • Values per kg lbm remained below baseline for duration of pregnancy • Individual variation was high

20. Poppitt et al., cont. • Energy sparing mechanisms may act via a suppression of metabolism in women on habitually low intakes. • This maintains positive balance in the mother and protects the fetus from growth retardation

21. Prentice and Goldberg. Energy Adaptations in human pregnancy: limits and long-term consequences. Am J Clin Nutr. 2000;71(supple):1226S-32S.

23. Longitudinal assessment of energy balance in well-nourished, pregnant women (Koop-Hoolihan et al, AJCN, 1999) • N=16, SF area • 10 became pregnant • BMI range was 19-26 • Mean weight gain at 36 weeks was 11.6 + 4 kg • Mean birth weight was 3.6 kg

24. Koop-Hoolihan, cont • Protocol: 5 times before pregnancy, 3 times during, once 4-6 weeks postpartum • RMR (resting metabolic rate/metabolic cart) • DIT (diet induced thermogenesis/metabolic cart) • TEE (total energy expenditure/doubly labeled water) • AEE (activity energy expenditure/difference between TEE and RMR) • EI (energy intake/3 day food records) • Body composition- densitometry, tbw, bmc with absorptiometry

25. Koop-Hoolihan, cont • Women with the largest cumulative increase in RMR deposited the least fat mass (this was the only prepregnant factor that predicted fat mass gain) • In all indices there was large individual variation • Average total energy cost of pregnancy was similar to work of Hytten and Leitch (1971) • Food intake records indicated 9% increase in kcals with pregnancy, but highly variable

26. Weight Gain in Pregnancy • Components & patterns • IOM recommendations • 1990 • 2009

27. Components of Weight Gain

28. Patterns of Maternal Fat Accretion

29. National Pregnancy Nutrition Surveillance http://www.cdc.gov/pednss/pnss_tables/html/pnss_national_table16.htm

30. Percent of Women Gaining <7.3 kg Hicky, CA. Am J Clin Nutr. 2000;71(supple):1364S-70S.

31. Characteristics of Women Associated with Inadequate Weight Gain • Lower education levels • Unmarried • Aged > 30 years • Smoking • Multiple parity • Unintended pregnancy • Psychosocial characteristics such as attitude toward weight gain, social support, depression, stress, anxiety, and self-efficacy. • Hicky, CA. Am J Clin Nutr. 2000;71(supple):1364S-70S.

32. 1990 IOM Recommendations Institute of Medicine. Nutrition during pregnancy, weight gain and nutrient supplements. Report of the Subcommittee on Nutritional Status and Weight Gain during Pregnancy, Subcommittee on Dietary Intake and Nutrient Supplements during Pregnancy, Committee on Nutritional Status during Pregnancy and Lactation, Food and Nutrition Board. Washington, DC: National Academy Press, 1990

33. Cogswell M, Serdula M, Hungerford D, Yip R. Gestational weight gain among average-weight and overweight women—what is excessive? Am J Obstet Gynecol 1995;172:705–12

34. 1990:Recommended total weight gain in pregnant women by prepregnancy BMI (in kg/m2) Weight-for-height category Recommended total gain (kg) Low (BMI <19.8) 12.5–18 Normal (BMI 19.8–26.0) 11.5–16 High (BMI >26.0–29.0)2 7–11.5 Adolescents and black women should strive for gains at the upper end of the recommended range. Short women (<157 cm) should strive for gains at the lower end of the range. The recommended target weight gain for obese women (BMI >29.0) is 6.0.

35. Incidence of adverse outcomes for 6690 pregnancies in San Francisco Parker J, Abrams B. Prenatal weight gain advice: an examination of the recent prenatal weight gain recommendations of the Institute of Medicine. Obstet Gynecol 1992;79:664–9

36. Percentage of US women with normal prepregnancy weights who retained >9 kg 10–24 mo postpartum relative to prepregnancy weight (Parker J, Abrams B. Differences in postpartum weight retention between black and white mothers. Obstet Gynecol 1993;81:768–74)

37. Percentage of US Women Who Gained >40 pounds during pregnancy(MMWR, February 2008) (source = birth certificates; singleton delivery only)

38. Prepregnancy Obesity*Washington State,1992-2005 *Obesity is defined as prepregnancy weight > 200 lbs Morbid obesity is defined as prepregnancy weight > 275 lbs

39. Obesity by Parity and Race/EthnicityWashington State, 2003-2005

40. Weight Gain During Pregnancy: Reexamining the Guidelines (IOM, 2009) • New Guidelines • Conceptual Framework • Composition and Components of Weight Gain • Determinants of Weight Gain • Maternal Consequences of Weight Gain • Child Consequences of Weight Gain • Determining Optimal Weight Gain • Achieving Recommendations

43. 2009 Guidelines for Specific Populations

45. Determinants of Gestational Weight Gain

46. Determinants: Social & Policy Findings

47. Determinants: Genetics • Maternal: insufficient evidence • Fetal: GWG associated with birthweight; preliminary conclusions about fetal genotype and birthweight: (a) there is a fetal genotype effect on weight at birth (about 30 percent of the adjusted variance) (b) both parents’ genes influence birth weight with a stronger effect for maternal genes (c) specific allelic variants have been associated with weight at birth (d) mutations in GCK and HNF1β are associated with low birth weight (e) mutations in HNF4α are associated with high birth weight (f) a few quantitative trait loci on chromosomes 6, 10, and 11 have been uncovered from genome-wide linkage scans

48. Determinants: Maternal Factors

49. Determinants: Maternal Behaviors “There remains a lack of information to relate dietary intake or physical activity to GWG even though they are primary determinants of weigh gain in non-pregnant individuals.”

50. Consequences of GWG for Mother • Strong association between high GWG &: • increased risk of cesarean delivery • postpartum weight retention (3 mos to 3 yr) • Modest association: • failure to initiate breastfeeding • Inconclusive evidence: • pregnancy complications like glucose intolerance and gestational hypertensive disorders • long term health consequences