Perinatal outcome in pregnancy complicated by massive obesity.

OBJECTIVE: Our objective was to determine the impact of massive obesity during pregnancy, defined as maternal weight > 300 pounds, on perinatal outcome. STUDY
DESIGN: A case-controlled study was conducted. Between Jan. 1, 1986, and Dec. 31, 1990, 111 pregnant women weighing > 300 pounds who were delivered at Long Beach Memorial Women's Hospital were identified with a perinatal data base search. A control group matched for maternal age and parity was selected, and perinatal variables were compared between groups. To control for potential confounding medical complications, massively obese patients with diabetes and/or chronic hypertension antedating the index pregnancy were excluded from the obese group, and the data were reanalyzed. The Student t test chi 2, and Fisher's exact statistical analysis were used where appropriate.
RESULTS: Massively obese pregnant women are significantly more likely to have a multitude of adverse perinatal outcomes, including primary cesarean section (32.4% vs 14.3%, p = 0.002), macrosomia (30.2% vs 11.6%, p = 0.0001), intrauterine growth retardation (8.1% vs 0.9%, p = 0.03), and neonatal admission to the intensive care unit (15.6% vs 4.5%, p = 0.01). They also are significantly more likely to have chronic hypertension (27.0% vs 0.9%, p < 0.0001) and insulin-dependent diabetes mellitus (19.8% vs 2.7%, p = 0.0001). However, when those massively obese pregnant women with diabetes and/or hypertension antedating pregnancy are excluded from analysis, no statistically significant differences in perinatal outcome persisted.
CONCLUSION: Massively obese pregnant women are at high risk for adverse perinatal outcome; however, this risk appears to be related to medical complications of obesity.