Background: Obesity, a common condition in developed countries, is recognized as a threat to health.

Objectives: To describe the distribution of weight in pregnant women and evaluate the influence of obesity on pregnancy outcome in a high parity northern Israeli population.

Methods: The study included 887 women who gave birth in the Western Galilee Medical Center during the period August to November 1995. The patients were classified as underweight, normal weight, overweight, or obese according to body mass index. Maternal demographic, obstetric, and perinatal variables were compared. A control group of 167 normal weight women were matched with the obese group for maternal age, parity, and gestational age.

Results: Obese mothers had a higher incidence of gestational diabetes and pregnancy-induced hypertension compared to normal weight mothers (5.4% vs. 1.8%, and 7.2% vs. 0.6% respectively, P<0.01), a higher rate of labor induction (20.4% vs. 10.2%, P<0.01), and a higher cesarean section rate (19.6% vs.10.8%, P<0.05). There was also a significant difference in the prevalence of macrosomia in the offspring (16.8% vs. 8.4%, P<0.05).

Conclusion: Obese pregnant women are at high risk for complications during delivery and therefore need careful pre-conception and prenatal counseling, as well as perinatal management.