Relevant Obstetric Factors for Cerebral Palsy: From the Nationwide Obstetric Compensation System in Japan

OBJECTIVE The aim of this study was to identify the relevant obstetric factors for cerebral palsy (CP) after 33 weeks' gestation in Japan. STUDY DESIGN This retrospective case cohort study (1:100 cases and controls) used a Japanese national CP registry. Obstetric characteristics and clinical course were compared between CP cases in the Japan Obstetric Compensation System for Cerebral Palsy database and controls in the perinatal database of the Japan Society of Obstetrics and Gynecology born as live singleton infants between 2009 and 2011 with a birth weight ≥ 2,000 g and gestation ≥ 33 weeks. RESULTS One hundred and seventy-five CP cases and 17,475 controls were assessed. Major relevant single factors for CP were placental abnormalities (31%), umbilical cord abnormalities (15%), maternal complications (10%), and neonatal complications (1%). A multivariate regression model demonstrated that obstetric variables associated with CP were acute delivery due to non-reassuring fetal status (relative risk [RR]: 37.182, 95% confidence interval [CI]: 20.028-69.032), uterine rupture (RR: 24.770, 95% CI: 6.006-102.160), placental abruption (RR: 20.891, 95% CI: 11.817-36.934), and preterm labor (RR: 3.153, 95% CI: 2.024-4.911), whereas protective factors were head presentation (RR: 0.199, 95% CI: 0.088-0.450) and elective cesarean section (RR: 0.236, 95% CI: 0.067-0.828). CONCLUSION CP after 33 weeks' gestation in the recently reported cases in Japan was strongly associated with acute delivery due to non-reassuring fetal status, uterine rupture, and placental abruption.