The relationship between maternal weight gain in pregnancy and newborn weight.

AIM: This study investigated the impacts of different pre-pregnancy body mass indexes and gestational weight gain on the risk of delivering a high birth weight infant in China.

METHODS: A retrospective cohort study was conducted from 2013 to 2014 in the Maternal and Child Health Care Hospital of Jinan City, Shandong Province and 2415 women who had a singleton birth were included in the study. A logistic regression model and restricted cubic spline regression were used to analyse the association.

FINDINGS: The risk of delivering a high birth weight infant increases when the mother's pre-pregnancy body mass index exceeds 24kg/m2 . Compared with women whose pre-pregnancy body mass index was 21kg/m2 , the adjusted risk of delivering a high birth weight infant doubled when the mother's pre-pregnancy body mass index was 29kg/m2 , and nearly tripled when the mother's pre-pregnancy body mass index was 31kg/m2 . Compared with women who had a gestational weight gain of 12.0kg, women having a gestational weight gain of 20.0kg, 22.0kg, and 26.0kg had a 1.7-, 2.2-, and 3.5-fold increased risk of delivering a high birth weight infant. When the mother experiences a gestational weight gain greater than 27kg, the risk of delivering a high birth weight infant is at least 4-fold greater than that for a mother who has a gestational weight gain of 12.0kg.

CONCLUSIONS: Proposed strategies to raise public awareness of the risks to infants posed by high maternal pre-pregnancy body mass index and gestational weight gain are required. All clinical recommendations and measures are for all pregnant women, not just overweight and obese pregnant women.