Intrapartum risk factors for neonatal encephalopathy leading to cerebral palsy in women without apparent sentinel events

Aim To determine intrapartum factors associated with neonatal encephalopathy leading to cerebral palsy (NE-CP). Methods A total of 70 NE-CP patients who fulfilled study criteria (cephalic singleton pregnancy with attempted vaginal delivery [AVD] at gestational week [GW] ≥36; intrapartum occurrence of non-reassuring fetal status without apparent cause following reassuring fetal status on admission; and development of NE-CP) were compared with 210 AVD controls who had 1- and 5-min Apgar score ≥8 matched for GW, maternal parity, and use of uterotonics. Suboptimal care was defined as delayed reaction due to misinterpretation of fetal heart rate (FHR) tracing, or inappropriate trial of instrumental delivery (TOID). Successful and failed TOID were defined as vaginal and cesarean delivery after TOID, respectively. The 210 controls were assumed not to have had suboptimal care. Results The rates of successful (34% vs 12%) and failed TOID (11% vs 0.0%), cesarean section (34% vs 14%), suboptimal care (57% vs 0.0%), pregnancy-induced hypertension (11% vs 2.4%), birthweight ≥3800 g (8.6% vs 1.9%), subgaleal hemorrhage (16% vs 0.0%) were significantly higher in NE-CP patients than in controls. Selection with the stepwise method and logistic regression analysis identified four independent risk factors for NE-CP: suboptimal intrapartum care (OR, 2.21; 95%CI: 1.99–2.47), cesarean section (OR, 1.19; 95%CI: 1.08–1.31), successful TOID (OR, 1.14; 95%CI: 1.03–1.25), and hypertension (OR, 1.20; 95%CI: 1.01–1.42). Conclusions Training programs for improved interpretation of FHR tracing and appropriate TOID are required to prevent NE-CP among healthy and mature fetuses in Japan.