Intrapartum fetal heart rate patterns preceding terminal bradycardia in infants (>34 weeks) with poor neurological outcome: A regional population-based study in Japan

• Published in: The journal of obstetrics and gynaecology research Vol. 41; no. 11; pp. 1738 - 1743
• Main Authors: Kodama, Yuki, Sameshima, Hiroshi, Yamashita, Rie, Oohashi, Masanao, Ikenoue, Tsuyomu
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.11.2015
• Subjects: Adult; Bradycardia - complications; Bradycardia - diagnosis; Brain Diseases - etiology; cerebral palsy; Female; fetal bradycardia; Fetal Death; Fetal Diseases - diagnosis; fetal heart rate monitoring; Fetal Monitoring; Heart Rate, Fetal; Humans; Intellectual Disability - etiology; intrauterine infection; Japan; non-reassuring patterns; Pregnancy; Stillbirth; fetal bradycardia; fetal heart rate monitoring; cerebral palsy; intrauterine infection; non-reassuring patterns
• ISSN: 1341-8076; 1447-0756
• DOI: 10.1111/jog.12797

Aim Intrapartum fetal bradycardia necessitates immediate operative delivery. Our aim was to investigate the hypothesis that some non‐reassuring fetal heart rate (FHR) patterns were present before the onset of terminal bradycardia in infants who developed subsequent brain damage. Material and Methods From a population‐based study of 65 197 deliveries, 190 stillbirths, 115 neonatal deaths, and 136 neurologically high‐risk infants were registered by the Miyazaki Perinatal Conference. There were 15 cases of neurologically high‐risk infants born at >34 weeks of gestation exhibiting intrapartum terminal bradycardia. Focusing on the brain‐damaged infants, we retrospectively analyzed FHR patterns for at least 1 h prior to the bradycardia. Results Brain damage (cerebral palsy [n = 11] and mental retardation [n = 2]) was diagnosed at 2 years old in 13 out of 15 neurologically high‐risk infants. Two infants had bradycardia on admission. In the remaining 11 infants, FHR patterns were reassuring in six (55%) and non‐reassuring in five (45%), including late decelerations (n = 4) and variable decelerations (n = 2). Clinically relevant factors in the non‐reassuring group included intrauterine infection (n = 3), malpresentation with umbilical cord coiling (n = 1), and unknown causes (n = 1). Clinically relevant features in the reassuring group included cord prolapse (n = 1), vaginal breech delivery (n = 1), shoulder dystocia (n = 1), rupture of membranes (n = 1), and unknown causes (n = 2). Conclusion More than half of the brain‐damaged infants born at >34 weeks of gestation who exhibited intrapartum terminal bradycardia had unremarkable FHR patterns before abrupt‐onset bradycardia. For those with non‐reassuring patterns preceding bradycardia, intrauterine infection was the major sentinel event.