DEVELOPMENT OF FETAL MOVEMENT - FETAL HEART-RATE COUPLING FROM 20 WEEKS THROUGH TERM

This study documents the development of fetal heart rate (FHR) change in response to fetal movement (FM) in healthy fetuses from 20 weeks' g estational age through term. Thirty-one fetuses received 50 min of Dop pler-based monitoring at 20, 24, 28, 32, 36 and 38-39 weeks, FHR and F M were continuously digitized. A coupling index was computed as the pe rcentage of FMs associated with increases in FHR of 5 beats/min or mor e within -5 or +15 s of movement onset, The latency between FM onset a nd FHR change was also computed, as were the amplitude and duration of all movements. FM and FHR became more integrated with advancing gesta tion, Coupling increased and the latency between FM and FHR changes de creased. Maternal age, blood pressure and fetal sex did not affect FM- FHR coupling, but fetuses of women who reported greater stress in thei r daily lives and had faster heart rates displayed reduced coupling, T hese data suggest that the development of FM-FHR coupling reflects the development of the central nervous system during gestation, and that development may be affected by maternal factors.