The American College of Obstetricians and Gynecologists (ACOG) has released an opinion statement on issues specific to pregnancy in obese women. The statement, “Obesity in Pregnancy,” was published in the September 2005 issue of Obstetrics & Gynecology.

Women who are obese (i.e., those with a body mass index [BMI] of 30 kg per m² or greater) are at increased risk of complications of pregnancy such as gestational hypertension and diabetes, preeclampsia, fetal macrosomia, spontaneous abortion, cesarean delivery, neural tube defects in the fetus, and stillbirth. Estimation of fetal weight and interpretation of external fetal heart rate and patterns of uterine contraction also may be problematic in women who are obese. Infants who are large for their gestational age are more common in mothers who are obese, and these infants subsequently are at increased risk of childhood obesity. In addition, operative and postoperative complications such as excessive blood loss, longer operative time, wound infection, endometritis, and anesthetic challenges are more common in obese patients.

ACOG strongly encourages preconception assessment and counseling of women who are obese, with provision of education about the risks and potential complications for mother and fetus. Nutrition advice should be provided, and patients should be encouraged to make changes in diet and exercise before pregnancy is attempted. Weight loss also should be encouraged before initiation of infertility treatment because of the increased risk of spontaneous abortion in obese women who undergo this therapy. Counseling and exercise programs should continue after delivery.

Women who have had bariatric surgery should be counseled to avoid pregnancy during the postsurgery phase of rapid weight loss. Pregnant women who have had bariatric surgery should have levels of vitamin B₁₂, folate, iron, and calcium assessed to determine whether supplementation is necessary.

Prenatal weight gain recommendations should correspond to the Institute of Medicine guidelines: 25 to 35 lb (11.4 to 15.9 kg) for women with a BMI below 25 kg per m²; 15 to 25 lb (6.8 to 11.4 kg) for women with a BMI of 25 to 29 kg per m²; and 15 lb (6.8 kg) for women with a BMI of 30 or greater kg per m². In pregnant women who are obese, screening for gestational diabetes should be considered at presentation or in the first trimester, with screenings repeated throughout pregnancy if the results are negative.

Because of the increased likelihood of cesarean delivery and complications of surgery, ACOG recommends that pregnant women who are obese have an anesthesiology consultation before delivery. Because of the increased risk of wound breakdowns and infections in obese patients, antibiotic prophylaxis should be given if cesarean delivery is required. The use of graduated compression stockings, hydration, and early mobilization may be helpful during and after cesarean delivery.