Nutritional counseling is a central element of preconception care and the initial parental visit. The following are the weight gain recommendations, based on the Institute of Medicine (IOM) 2009 guidelines. Note, the IOM was renamed the National Academy of Medicine in 2015.

IOM Recommendations for Weight Gain in Pregnancy

Singleton pregnancy: 

• Underweight – BMI less than 18.5
  • Total weight gain: 28-40 lbs
  • Rate of gain in 2nd & 3rd trimesters: 1 lb/wk
• Normal weight: BMI between 18.5–24.9
  • Total weight gain: 25-35 lbs
  • Rate of gain in 2nd & 3rd trimesters: 1 lb/wk
• Overweight:  BMI between 25-29.9
  • Total weight gain: 15-25 lbs
  • Rate of gain in 2nd & 3rd trimesters: 0.6 lb/wk
• Obesity (all classes, I – III): BMI 30 and greater
  • Total weight gain: 11-20 lbs
  • Rate of gain in 2nd & 3rd gain: 0.5 lb/wk

Twin pregnancy:

• Normal weight: BMI between 18.5–24.9
  • Total weight gain: 37-54 lbs
  • Rate of gain in 2nd & 3rd trimesters: 1 lb/wk
• Overweight: BMI between 25-29.9 lbs
  • Total weight gain: 31-50 lbs
  • Rate of gain in 2nd & 3rd trimesters: 0.6 lb/wk
• Obesity (all classes, I – III): BMI 30 and greater
  • Total weight gain: 25-42 lbs
  • Rate of gain in 2nd & 3rd trimester: 0.5 lb/wk

Perinatal Risks for Not Meeting IOM Weight Gain Targets in Singletons (Goldstein et al., JAMA 2017)

Gestational weight gain below the recommendations

• Increased risk for SGA (odds ratio [OR], 1.53 [95% CI, 1.44-1.64]; absolute risk difference [ARD], 5% [95% CI, 4%-6%])
• Increased risk for preterm birth (OR, 1.70 [1.32-2.20]; ARD, 5% [3%-8%]) and
• Decreased risk for LGA (OR, 0.59 [0.55-0.64]; ARD, -2% [-10% to -6%])
• Decreased risk for macrosomia (OR, 0.60 [0.52-0.68]; ARD, -2% [-3% to -1%]);
• No difference for cesarean delivery (OR, 0.98 [0.96-1.02]; ARD, 0% [-2% to 1%])

Gestational weight gain above the recommendations

• Decreased risk for SGA (OR, 0.66 [0.63-0.69]; ARD, -3%; [-4% to -2%])
• Decreased risk for preterm birth (OR, 0.77 [0.69-0.86]; ARD, -2% [-2% to -1%])
• Higher risk of LGA (OR, 1.85 [1.76-1.95]; ARD, 4% [2%-5%])
• Higher risk for macrosomia (OR, 1.95 [1.79-2.11]; ARD, 6% [4%-9%]),
• Higher risk for cesarean delivery (OR, 1.30 [1.25-1.35]; ARD, 4% [3%-6%])

SYNOPSIS:

In a systematic review of over 1 million pregnant women, most did not meet the IOM targets, with 47% gaining more and 23% gaining less than IOM recommendations.  ACOG recommends using judgment and individualized care. Medications for weight management are not recommended during the time of conception or during pregnancy. Rather, dietary control, exercise and behavioral modification are the primary weight management strategies during pregnancy.

KEY POINTS:

• Obese women should be screened early for glucose intolerance and obstructive sleep apnea
• The optimal control of obesity should begin before conception
  • Weight loss before pregnancy is the most effective intervention to improve medical comorbidities
  • Both nonsurgical and surgical methods prior to pregnancy can have beneficial effects
• Management in labor and delivery
  • Allow a longer first stage of labor before performing a cesarean section for labor arrest
  • Obtain an early anesthesia consult
  • Consider early epidural placement
  • Consider using a higher preoperative antibiotic dose
  • Closure of the subcutaneous tissue with depth greater than 2 cm can significantly decrease the incidence of wound disruption
  • Consider pharmacologic thromboprophylaxis in addition to pneumatic compression devices for prevention of venous thromboembolism

Learn More – Primary Sources:

ACOG Committee Opinion No. 548: Weight Gain During Pregnancy

IOM: Weight Gain During Pregnancy: Reexamining the Guidelines

ACOG Practice Bulletin No. 230: Obesity in Pregnancy

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

Related ObG Topics:

Obesity in Pregnancy: Classification and Clinical Implications

Does BMI Impact Success of Vacuum-Assisted Vaginal Delivery?

Macrosomia: Determination of EFW and Recommendations for Delivery

Obesity and Stillbirth At Term – What is the Actual Risk?

Antibiotic Prophylaxis during Labor and Delivery

Are Obese Women Less Likely to Have Spontaneous Labor Onset?

Does Elective Induction Lower Risk for Adverse Obstetrical Outcomes in the Setting of Obesity

Is Bariatric Surgery Associated with Decreased Risks for Severe Birth Defects?

Maternal Overweight, Obesity and Congenital Malformations – How Strong is the Link?

NTDs and Pregnancy – Folic Acid Recommendations