A longitudinal study of diurnal variation in baseline fetal heart rate in one dichorionic-diamniotic twin pregnancy

A longitudinal study to analyse the diurnal variations in baseline fetal he art rate (FHR) and sustained fetal tachycardia (SFT) in twin pregnancy was performed on one dichorionic twin. Twenty-four hour FHR recordings on twins were made at 32, 34 and 36 weeks of gestation simultaneously. Significant diurnal variations were found in both twins in all gestational weeks. The d iurnal variations in baseline FHR of twins were highly correlated with no p hase-lag, No coincidence was recognized in the appearance of SFT between tw ins, These results suggest the maternal influence equally affects FHR in ea ch fetus of dichorionic twin since 32 weeks of gestation, while the appeara nce of SFT might be independent from maternal influence.