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

PLoS One. 2015 Jul 21;10(7):e0132650. doi: 10.1371/journal.pone.0132650. eCollection 2015.


Background: Controversy 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.

Objectives: A 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).

Design: Five 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.

Results: Six 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).

Conclusion: Despite 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.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Female
  • Humans
  • Infant, Newborn
  • Infant, Small for Gestational Age
  • Obesity / complications*
  • Obesity / pathology*
  • Pregnancy
  • Pregnancy Complications / diagnosis
  • Pregnancy Complications / epidemiology
  • Pregnancy Complications / pathology*
  • Pregnancy Outcome
  • Premature Birth / diagnosis
  • Premature Birth / epidemiology
  • Premature Birth / pathology
  • Weight Gain*
  • Weight Loss*