Associations Between Gestational Weight Gain and Adverse Birth Outcomes: A Population-Based Retrospective Cohort Study of 9 Million Mother-Infant Pairs

Abstract

BackgroundGestational weight gain (GWG) reflects maternal nutrition during pregnancy. However, the associations between maternal GWG and adverse birth outcomes are inconclusive.ObjectiveWe aimed to examine the associations between maternal GWG and adverse birth outcomes according to maternal pre-pregnancy body mass index (BMI) categories in a large, multiethnic and diverse population in the U.S.Study DesignWe used nationwide birth certificate data from the National Vital Statistics System to examine the association of GWG (below, within and above the Institute of Medicine [IOM] guidelines) with six adverse birth outcomes (preterm birth, low birthweight, macrosomia, small for gestational age [SGA], large for gestational age [LGA], and low Apgar score) according to the pre-pregnancy BMI categories (underweight to obesity grade 3). Multivariable logistic regression analyses were performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs).ResultsA total of 9,191,842 women aged 18–49 years at delivery with live singleton births were included. Among them, 24.5% of women had GWG below IOM guidelines, 27.6% within the guidelines, and 47.9% above the guidelines. Compared with maternal GWG within guidelines, GWG below guidelines was associated with higher odds of preterm birth (OR = 1.52, 95%CI = 1.51–1.53), low birthweight (OR = 1.46, 95%CI = 1.45–1.47) and SGA (OR = 1.44, 95%CI = 1.43–1.45). In contrast, maternal GWG above guidelines was associated with higher odds of macrosomia (OR = 2.12, 95%CI = 2.11–2.14) and LGA (OR = 2.12, 95%CI = 2.11–2.14). In addition, maternal GWG below or above guidelines had slightly higher odds of low Apgar score (below guidelines: OR = 1.04, 95%CI = 1.03–1.06, above guidelines: OR = 1.17, 95%CI = 1.15–1.18). The results were largely similar among women with GWG below or above guidelines across pre-pregnancy BMI categories of underweight, overweight, and obesity grade 1 to grade 3.ConclusionPregnant women with GWG below or above the IOM guidelines have increased odds of selected adverse infant birth outcomes. Monitoring maternal GWG could enable physicians to provide tailored nutrition and exercise advice as well as prenatal care to pregnant women to reduce the likelihood of adverse birth outcomes.

Impact of Gestational Weight Gain on Pregnancy Outcome

“…Cholecystitis and LGA were significantly higher in the weight gain > 13kg group than in other groups, while anemia and SGA were significantly higher in the weight loss group than in other groups. This was confirmed by Xi et al [12] , who found that high GWG (above IOM limits) was inversely related to preterm delivery, low birth weight, and SGA while positively correlated with macrosomia, LGA, and low Apgar scores. Also, Chen et al [11] found that the excessive GWG group had significantly greater adjusted risks of GHTN, preeclampsia, cesarean birth, and macrosomia than the sufficient GWG group.…”

Analysis and Comparison of Early Childhood Nutritional Outcomes Among Offspring of Chinese Women Under the Chinese 2021 and US 2009 Gestational Weight Gain Guidelines

“…Previous studies have shown that adherence to the NAM recommendations appears to achieve improved pregnancy outcomes 16 and that GWG outside the NAM recommendations may be associated with adverse pregnancy outcomes and unhealthy children's status. [17][18][19][20][21] It should be noted that obesity is excess adipose tissue and not excess weight. 22 Asian individuals possess a higher percentage of body fat at a lower body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and the ethnic specificity in fat store patterns is partially determined by genetics.…”

“…In 2009, the US National Academy of Medicine (NAM, formerly the Institute of Medicine) released revised GWG guidelines that have been widely adopted in many countries. Previous studies have shown that adherence to the NAM recommendations appears to achieve improved pregnancy outcomes and that GWG outside the NAM recommendations may be associated with adverse pregnancy outcomes and unhealthy children’s status …”

Comparison of the 2009 Institute of Medicine and 2021 Chinese guidelines for gestational weight gain: A retrospective population‐based cohort study

“…with greater risk of LGA, and lower risk of SGA and preterm birth, whereas GWG below the IOM guidelines was associated with greater risk of preterm birth and SGA in all (WHO-defined) BMI subgroups. 12 We found that inadequate GWG was associated with higher risk of preterm birth when the CNS guidelines were used, with a larger OR than obtained with the IOM guidelines. The consistency analysis suggested that the difference between recommendations lay primarily in the management of underweight and normal-weight populations.…”