THE INTERGENERATIONAL PREDISPOSITION TO OPERATIVE DELIVERY

Objective: To determine the risk of cesarean delivery for women who th emselves were born via operative delivery. Methods: A linked data base was constructed between the birth certificates of individuals born in Utah during 1947-1957 (parental cohort) and who subsequently became a parent of offspring born in Utah between 1970-1991 (offspring cohort) . Parental cohort women (cases) who had been delivered operatively (ce sarean delivery, mid- or high forceps) as well as women who had a sibl ing delivered by an operative procedure were matched (1:2) with parent al-cohort women born by spontaneous vaginal delivery (controls). Both cases and controls were selected based on having a record of at least one delivery in Utah during 1970-1991. Results: Women who were deliver ed by cesarean were at increased risk of subsequently delivering their children by cesarean (odds ratio [OR] 1.41, 95% confidence interval [ CI] 1.18-1.70; P < .001). Progressive risk was associated with parenta l delivery by mid- or high forceps (OR 1.72, 95% CI 1.20-2.47; P = .00 4), parental cesarean because of cephalopelvic disproportion alone (OR 1.83, 95% CI 1.16-2.88; P = .01), or parental cesarean for dysfunctio nal labor (OR 5.97, 95% CI 1.5-23.6; P < .001). The attributable risk for cesarean delivery to the contemporary population is 3.5%.