Gestational weight gain above or below the level recommended by the Institute of Medicine (IOM) guidelines resulted in significantly worse outcomes for mothers and babies, according to data from nearly 30,000 women.
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Previous studies of the relationship between gestational weight gain and maternal and neonatal outcomes have been limited by “small sample sizes, single sites, restricted reporting of outcomes, and a lack of racial-ethnic diversity,” Michelle A. Kominiarek, MD, of Northwestern University in Chicago and her colleagues wrote . To determine the effects of gestational weight gain on a large and more diverse population, the researchers conducted a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network’s Assessment of Perinatal Excellence study. The findings were published in Obstetrics & Gynecology.
Gestational weight gain above the amount recommended by IOM guidelines was significantly associated with adverse outcomes in neonates, including macrosomia (adjusted odds ratio, 2.66), shoulder dystocia (aOR, 1.74), and neonatal hypoglycemia (aOR, 1.60).
In further multivariate analysis, adverse maternal outcomes associated with gestational weight gain above that recommended by the guidelines included hypertensive diseases of pregnancy for any parity (aOR, 1.84) and increased risk of cesarean delivery in nulliparous and multiparous women (aORs, 1.44 and 1.26, respectively).
Gestational weight gain below the recommended amount was associated with both spontaneous (aOR, 1.50) and indicated (aOR, 1.34) preterm birth. Weight gain above the guidelines was associated with a greater risk of indicated preterm birth only (aOR, 1.24).
The study population included 29,861 women at 25 hospitals over a 3-year period. Of these, 51% had gestational weight gains above the amount recommended by the IOM guidelines and 21% had gestational weight gains below it. The researchers calculated gestational weight gain by subtracting prepregnancy weight from delivery weight or, if prepregnancy weight was not available, by subtracting weight at the first prenatal visit at 13 weeks of gestation or earlier from delivery weight.
The study findings were limited by the use of self-reported prepregnancy weight and the possible effects of changes to the guidelines with respect to obese patients, the researchers said. However, the results support those from previous studies, and the “noted strengths include analysis of 29,861 women representative of the United States with rigorous ascertainment of outcomes and calculation of gestational weight gain to account for the wide range of gestational ages at delivery,” Dr. Kominiarek and her associates wrote.
Overall, the data support efforts to educate women on health behaviors and how gestational weight gain affects them and their infants, and additional research is needed to help women meet their goals for appropriate gestational weight, the researchers concluded.
SOURCE: Kominiarek MA et al. Obstet Gynecol. 2018 Oct;132(4):875-81.