A Body Mass Index and Weight Gain in Pregnant Women With HIV: A National Study in Italy

Although most of the women (69.4%) had a normal BMI at start of pregnancy, only 37% had an adequate weight gain during pregnancy. Inadequate body weight gain was more common (44.8%) than excessive weight gain (18.2%), but 40% of overweight women and 50% of obese women had an excessive weight gain in pregnancy, with about 9% of the women in these categories gaining >18 kg during pregnancy (Table 1). Only 1.9% of the women had a vaginal delivery; elective and nonelective cesarean deliveries accounted for 81.3% and 16.7% of deliveries, respectively. Compared to underweight/normal women, overweight/obese women had similar occurrences of preterm delivery (23.4% vs 22.7%, P = .871), significantly lower rates of low birthweight (14.2% vs 24.2%, P = .007) and nonelective cesarean deliveries (11.7% vs 18.3%, P = .042), and a significantly higher occurrence of fasting plasma glucose >92 mg/dL at 20–28 weeks (12.1% vs 6.6%, P = .027), hypertension during pregnancy (6.4% vs 2.7%, P = .019), and gestational age–adjusted birthweight >90th percentile (15.5% vs 5.0%, P < .001). Complications of delivery, major birth defects, and HIV transmission were similar between the 2 groups (7.3% vs 7.6%, P = .881; 2.6% vs 3.5%, P = .589; and 0.8% vs 0.5%, P = .661, respectively). An inadequate weight gain during pregnancy was associated with an increased risk of nonelective cesarean delivery (OR, 1.589 [95% CI, 1.077–2.346], P = .020). Excessive weight gain during pregnancy was not associated with either hypertension (OR, 1.364 [95% CI, .537–3.465], P = .514) or 20–28 week glucose level of >92 mg/dL (OR, 0.841 [95% CI, .399–1.772], P = .648), but was significantly associated with birthweight >90th percentile (OR, 2.271 [95% CI, 1.229–4.195], P = .009), and appeared to be protective against low birthweight (OR, 0.544 [95% CI, .323–.918], P = .023) and birthweight <10th percentile (OR, 0.297 [95% CI, .117–.752], P = .007). Our data show that almost one-quarter of pregnant women with HIV are overweight or obese at the beginning of pregnancy, and that women in these groups have a significantly increased occurrence of diabetes and hypertension in pregnancy. The risks of low birthweight and nonelective cesarean delivery were higher in the underweight/normal BMI categories. Consistent with data from the general population [10], only 37% of pregnant women with HIV had an adequate weight gain in pregnancy. Excessive weight gain during pregnancy was particularly frequent among overweight and obese women. Inadequate weight gain was associated with nonelective cesarean delivery, and excessive weight gain with large-for-gestational-age infants. BMI and weight gain represent modifiable risk factors that should be adequately identified and corrected in order to reduce adverse pregnancy outcomes in this population.