Weight Loss Instead of Weight Gain within the Guidelines in Obese Women during Pregnancy: A Systematic Review and Meta-Analyses of Maternal and Infant Outcomes

Abstract

BackgroundControversy exists about how much, if any, weight obese pregnant women should gain. While the revised Institute of Medicine guidelines on gestational weight gain (GWG) in 2009 recommended a weight gain of 5–9 kg for obese pregnant women, many studies suggested even gestational weight loss (GWL) for obese women.ObjectivesA systematic review was conducted to summarize pregnancy outcomes in obese women with GWL compared to GWG within the 2009 Institute of Medicine guidelines (5–9 kg).DesignFive databases were searched from 1 January 2009 to 31 July 2014. The Cochrane Handbook for Systematic Reviews of Interventions and the PRISMA Statement were followed. A modified version of the Newcastle-Ottawa scale was used to assess individual study quality. Small for gestational age (SGA), large for gestational age (LGA) and preterm birth were our primary outcomes.ResultsSix cohort studies were included, none of which assessed preterm birth. Compared to GWG within the guidelines, women with GWL had higher odds of SGA <10th percentile (adjusted odds ratio [AOR] 1.76; 95% confidence interval [CI] 1.45–2.14) and SGA <3rd percentile (AOR 1.62; 95% CI 1.19–2.20) but lower odds of LGA >90th percentile (AOR 0.57; 95% CI 0.52–0.62). There was a trend towards a graded relationship between SGA <10th percentile and each of three obesity classes (I: AOR 1.73; 95% CI 1.53–1.97; II: AOR 1.63; 95% CI 1.44–1.85 and III: AOR 1.39; 95% CI 1.17–1.66, respectively).ConclusionDespite decreased odds of LGA, increased odds of SGA and a lack of information on preterm birth indicate that GWL should not be advocated in general for obese women.

Obesity and pregnancy: mechanisms of short term and long term adverse consequences for mother and child

“…179 Furthermore, our group reported an increased risk of SGA and decreased lean body mass (head circumference and length) in neonates of overweight or obese women with inadequate GWG. 180 Therefore, unless new compelling data become available, overweight and obese women should comply with IOM guidelines on GWG.…”

Gestational Weight Gain: Association with Adverse Pregnancy Outcomes

“…Many of these studies cite both a maternal and fetal benefit including lower risk for hypertensive disorders in pregnancy, decreased rate of emergency CD, and a decreased risk for macrosomia. 6,7,14,15 A recent meta-analysis evaluating GWL among obese women and pregnancy outcomes found an approximate doubling of the odds of SGA <10th percentile in obese women but an approximate halving of the odds of LGA >90th percentile in those women who lost weight during pregnancy. Additionally, they found an association with GWL and decreased odds of CD and shoulder dystocia.…”

“…Additionally, they found an association with GWL and decreased odds of CD and shoulder dystocia. 15 The effect of GWL in obese women on PTB was not assessed in any of the included studies. In a recent committee opinion from the ACOG Committee it is recommended that "for an obese pregnant woman who is gaining less weight than recommended but has an appropriately growing fetus, no evidence exists that encouraging increased weight gain to conform with the updated IOM guidelines will improve maternal and fetal outcomes" 16 .…”

A Mediterranean Diet with an Enhanced Consumption of Extra Virgin Olive Oil and Pistachios Improves Pregnancy Outcomes in Women Without Gestational Diabetes Mellitus: A Sub-Analysis of the St. Carlos Gestational Diabetes Mellitus Prevention Study

“…Weight gain 3 kg below the designated target according to BMI was categorized as insufficient weight gain. Weight gain 3 kg above the designated target according to BMI was categorized as excessive weight gain [21][22][23]. At each visit, the dietary recommendations were individualized to fit gestational weight gain recommendations according to pregestational BMI, in the context of usual recommendations.…”