Examination of the Impact of Maternal Weight Gain on Abnormalities of Fetal Growth in Women of Varying Body Mass Indices

Magner Kristin

doi:10.16966/2380-5528.112

Abstract

Objective: To analyze the association between maternal weight gain and abnormalities of fetal growth. Methods: We calculated mean weight gain in pregnancies resultingin small for gestational age (SGA) or large for gestational age (LGA) fetuses, with normal growth as the referent. We classified pregnancies as to whether they had met, gained under or exceeded 2009 Institute of Medicine recommendations (IOMR) and evaluated the rate of SGA and LGA. Multivariateand linear regression analyses were performed. Results: We found similar weight gains in women with normal versus SGA fetuses, 10.5 versus 9.6 kg respectively, LGA fetuses had a significantly higher weight gain, 13.8 kg (p<0.01). We found higher rates of SGA in NW women who gained under versus met IOMR (17.5 versus 11.6%), but not in OW women (10 versus 12 %, p=0.58).Obese women had a higher rate of SGA when women gained under versus met IOMR (10.7 vs 5.0%, p=0.02), however once controlled for confounders, this association was no longer significant, aOR 1.23 (0.82-1.86).The rate of SGA in obese women who gained under IOMR, 10.7%, was less than the baseline risk of SGA in NW women, 11.6%,indicating loss of a protective effect in obese women. Conclusion: Weight gain in women who deliver normal weight fetuses and SGA fetuses is clinically similar, however in NW women there is a greater rate of SGA when weight gain is insufficient. This increase in SGA is not found in OW women, nor is it found in obese women, when adjusted for confounding variables. Any increase in SGA in obese women when they gain under IOMR appears to be secondary to a loss of a protective effect.

Highlights

Obesity has reached epidemic proportions in the United States and has been classified as a “disease” by the American Medical Association [1]
Other studies have demonstrated that limited weight gain in obese and overweight women can reduce the risk of some pregnancy comorbidities such as gestational diabetes, preeclampsia, and operative delivery) [11,12,13]
As expected, higher rates of pregestational diabetes and gestational diabetes were seen in women with a large for gestational age (LGA) fetus

Summary

Introduction

Obesity has reached epidemic proportions in the United States and has been classified as a “disease” by the American Medical Association [1]. Several studies have demonstrated increases in macrosomia, diabetes, preeclampsia, cesarean delivery and adverse maternal and neonatal outcomes with excessive weight gain [4,5,6,7,8,9,10]. Other studies have demonstrated that limited weight gain in obese and overweight women can reduce the risk of some pregnancy comorbidities such as gestational diabetes, preeclampsia, and operative delivery) [11,12,13]. Whether the overweight and obese have increased rates of SGA when there is limited maternal weight gain is understudied. For this reason, the IOM called for additional research in the morbidly obese to help determine recommendations for weight gain in this population

Methods

Results

Conclusion