BACKGROUND AND PURPOSE:

• Most women in the United States significantly increase their caloric consumption during pregnancy, with many exceeding the recommended IOM guidelines
• Goldstein et al. (JAMA, 2017) conducted a systematic review comparing women who gained more or less than the recommended 2009 IOM guidelines to determine if there is actually an association with maternal and infant outcomes

METHODS:

• Systematic review and meta-analysis
• 1,309,136 pregnant women were included among 23 studies that met inclusion criteria
• Primary outcomes:
  • Small for gestational age (SGA)
  • Preterm birth
  • Large for gestational age (LGA)
• Secondary outcomes:
  • Macrosomia
  • Cesarean delivery
  • GDM

RESULTS:

• Gestational weight gain was below IOM guidelines in 23% of pregnancies and above guidelines in 47%
• Woman who exceeded weight gain guidelines had
  • Lower risk for SGA (odds ratio 0.66; 95% CI 0.55-0.64)
  • Lower risk for preterm birth (odds ratio 0.77; 95% CI 0.69-0.86)
  • Higher risk for LGA (odds ratio 1.85; 95% CI 1.76-1.95)
  • Higher risk for macrosomia (odds ratio 1.95; 95% CI 1.79-2.11)
  • Higher risk for cesarean delivery (odds ratio 1.30; 95% CI 1.25-1.35)
• Woman who gained less weight than guidelines had
  • Higher risk for SGA (odds ratio 1.53; 95% CI 1.44-1.64)
  • Higher risk for preterm birth (odds ratio 1.70; 95% CI 1.32 – 2.20)
  • Lower risk for LGA (odds ratio 0.59; 95% CI 0.55-0.64)
  • Lower risk for macrosomia (odds ratio 0.60; 95% CI 0.52-0.68)
  • No difference in cesarean delivery
• Data was not adequate to assess GDM

CONCLUSION:

• Both low and high weight gain outside the IOM targets were associated with adverse outcomes in both mother and infants
  • The authors point out that this study assessed association and not causation
• Friedmann and Balayla applied a novel model to address gestational age bias (see ‘Learn More – Primary Sources’ below)
  • Analysis of over approximately 1.5 million women with normal prepregnancy weight did not demonstrate increased risk of infant death in the first year of life among those with excessive or inadequate weight gain using the IOM standards
  • The authors suggest that their novel analytic model may be helpful in future research on BMI and weight gain

Learn More – Primary Sources:

Association of Gestational Weight Gain With Maternal and Infant Outcomes: A Systematic Review and Meta-analysis

Gestational weight gain and the risk of infant mortality amongst women with normal prepregnancy BMI: the Friedmann-Balayla model

Related ObG Topics:

Recommended Weight Gain and Obesity Management in Pregnancy

Does Exercise During Pregnancy Impact Hypertension or Macrosomia?

Obesity in pregnancy – classification and clinical implications