Analysis of antenatal-onset cerebral palsy secondary to transient ischemia in utero using a national database in Japan

Aim: We conducted a retrospective analysis of summary medical reports of children diagnosed with cerebral palsy (CP) to identify clinical features of antenatal onset of CP secondary to transient ischemia in utero. Methods: The 658 brief summary reports available in the Japan Obstetric Compensation System for Cerebral Palsy were screened, and we identified cases of singleton pregnancy, delivered at gestational age ≥ 33 weeks and those with cord blood gas pH ≥ 7.20. Of the 137 cases identified, 84 were excluded for the following reasons: no evidence of ischemic brain lesion, clear post-natal causative factor of CP, presence of a congenital condition, and sentinel hypoxic event, such as uterine rupture. The demographic profiles of the 53 cases included in our analysis were compared to identify those with and without an abnormal variability in fetal heart rate. Results: Between-group comparison identified an association between abnormal heart rate variability and a lower Apgar score at 1 min (2 vs 6; P < 0.001) and 5 min (5.5 vs 8; P = 0.002), and more frequent episodes of fetal movement loss (41% vs 10%; P = 0.027). An hypoxic event ≤ 1 week before delivery was more likely to be associated with abnormal heart rate variability (89%) and low Apgar score (82%), while events at > 1 week were associated with development of polyhydramnios (44%). Conclusion: In utero transient ischemic events can contribute to term or near-term CP. Careful follow-up is recommended for fetuses with a history of fetal movement loss, abnormal variability in heart rate, and polyhydramnios of unknown causes.