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To review the perspectives and supporting research in the decision regarding the reduction of maternal weight gain as an appropriate approach for preventing obesity.

Article inclusion criteria not described.

None specifically mentioned.

Recruitment:  article selection methods not described.

Design:  Narrative Review.

Blinding Used (if applicable):  not applicable

Intervention (if applicable):  not applicable

Statistical Analysis:  not performed

Timing of Measurements:  not applicable

Dependent Variables:  not applicable

Independent Variables:  not applicable

Control Variables:  not applicable

Initial N:  51 references cited

Attrition (Final N):  51

Age:  not mentioned

Ethnicity:  not mentioned

Other relevant demographics:

Anthropometrics:

Location:  Worldwide studies 

Effect of maternal weight gain on birthweight

Eastman & Jackman, 1968 compared women who gained 11-20 lb. With those who gained 31-40 lb. Shieve, et al., 1998 compared birthweights of infants from mothers who gained less or more than the recommended amounts.  Parker & Abrams, 1992 examined the effect of maternal weight gain within or outside the recommended range. 

Maternal weight gain was significantly related to infant birthweight.

+275 g in birth weight of infants among women who gained 31-40 lb. Regardless of whether the women were heavy (140-159 lb) or low weight (110-119 lb.) before pregnancy.

Birthweight increased as maternal weight gain increased within all 4 BMI groups for non-Hispanic white, non-Hispanic black, and Hispanic mothers.

An increase of 47 to 72 g in mean birthweight was observed for women who gained in the upper half of the recommended range compared to women who gained in the lower half of the range.

Higher weight gain decreased the portion of birthweights <10^th % and raised the portion above the 90^th % by almost exactly the same amount.

Importance of optimal birthweight

Rees JM, et. al. examined neonatal mortality rates at 500 g intervals of birthweight in infants of black and white women.  Seeds & Peng, 1998, evaluated fetal and neonatal mortality by birthweight. McIntire et al, 1999 looked at respiratory distress in preterm infants.

Minimum neonatal mortality was observed at 3500 to 4499 g for infants of white mothers and 3000 to 3999 g for infants of black mothers. 

More than 50% of births to white adult mothers were in birthweight intervals just below those levels (2500-2999 g and 3000 – 3499 g) where neonatal mortality was 155% to 350% higher than in the optimal birthweight ranges.

32% of births among adult black mothers were in the birthweight category just below optimal (2500 – 2999 g) with a 181% higher neonatal mortality.

Combined fetal and neonatal mortality rate for term births was minimized when birthweight was  >3500 g, although it rose again at birthweights of  >4500 g.

Deaths/1000 live births by birthweight:

2500-2749         4.3

2750-2999         2.83

3000-3249         1.53

>4500                3.6

The incidence of respiratory distress among 12,317 infants born at 28 to 36 wk gestation rose from a low of 4% to more than 20% as birthweight decreased to below the 10^th % from the 91^st to 99^th % for age.

Minimum mortality for infants born to obese women occurred between 7 and 21 lb maternal weight gain, compared to 22 to 32 lb in normal weight women.

Brachial plexus injury occurred in 3% of neonates weight 4500 to 5000 g and in 6.7% of those weighing >5000 g.

<14% of these injuries occurred in infants weighing 4500 to 5000 g.

Concerns about maternal weight gain.

Naeye RL looked at infant mortality born to obese women.  Bryant et al. 1998 looked at the rate of brachial plexus injury in neonates weighing 4500 to >5000 g.

10 of the 25 women (40%) were overweight or obese before pregnancy and all of them gained excessive weight during pregnancy. 

64% of the women had gained excessively during pregnancy and all overweight and obese women had gained excessively.

Women gained an average of 38 lb and lost 21 lb by 2 mos postpartum but no additional weight had been lost by 6 mos postpartum.

Postpartum Weight 

Lederman reviewed medical records of 29 black or Hispanic mothers who delivered at St. Luke’s (NYC) in 1998.  Lederman obtained prepregnancy weight and height and maximum pregnancy weight from 47 black first time mothers at 2 wks, 2 and 6 mos postpartum.

41% of 22 women interviewed at 6 mos postpartum were in a higher BMI group than before pregnancy and 18% of the normal weight women were newly overweight or obese.

Birthweight rises with increased pregnancy weight gain, and perinatal and neonatal mortality fall as birthweight increases in both preterm and term infants.

Pregnancy weight gain exceeding current recommendations is associated with increases in maternal fat gain, pregnancy complications, and delivery problems and should be discouraged. 

Postpartum weight loss is essential to prevent permanent weight increase.  Smoking cessation during pregnancy, reduced postpartum physical activity and other lifestyle changes can contribute to increased postpartum weight. 

Health care providers can help to reduce obesity risk by regularly monitoring women’s weights; promoting appropriate prepregnancy weight, pregnancy weight gain, and postpartum weight loss; and explicitly encouraging maintenance of an active lifestyle.

University/Hospital:

St. Luke's Roosevelt Hospital

This review supports the IOM recommendations for weight gain during pregnancy.

Research is needed to evaluate causes for low birthweight in addition to maternal weight gain, for example, factors that contribute to IUGR and premature birth.