Diurnal variations in baseline fetal heart rate, maternal heart rate and movement in a twin pregnancy

Abstract

In order to clarify the relationship between the diurnal variations in baseline fetal heart rate (BFHR) and maternal factors, simultaneous 24 h recordings of fetal heart rate, maternal heart rate (MHR) and maternal movement (MM) were made on one pregnant woman with a monochorionic twin pregnancy at 31, 34 and 36 weeks. The diurnal variations in BFHR of twins were highly correlated with no phase-lag. Although BFHR was correlated with MHR and MM at 31 and 36 weeks with phase-lag, there was no correlation between them at 34 weeks, despite the synchronization of BFHR between twins. It was suggested MHR and MM might not drive the diurnal variation of BFHR directly, because BFHR, MHR and MM did not always correlate.