Fetal cardiac responding: a correlate of birth weight and neonatal behavior.

Certain intrapartum fetal heart-rate (FHR) patterns are associated with low Apgar scores and other neonatal risks. Intrapartum FHR has been the subject of extensive clinical investigation, but only occasional reference is made to the possible behavioral correlates of this phenomenon. The current investigation found that neonates classified as FHR decelerators had lower birth weights and shorter gestational ages than FHR accelerators. Decelerators exhibited higher baseline heart rate and experienced more frequent uterine contractions than accelerators. Neurobehavioral assessment of these neonates indicated that decelerators had more abnormal reflex ratings and were less behaviorally organized than heart-rate accelerators. The results indicate that FHR responses are associated with prenatal growth, maturity, and possibly stress tolerance, and that intrapartum FHR responses be related to nonoptimal neonatal behavior.