ETHNICITY AND FETAL HEART-RATE VARIATION

Objective: To determine the effect of ethnicity on fetal heart rate (F HR) variation. Methods: A prospective study was conducted of 27 consec utive black women (of African or Caribbean ethnic origin) and 79 conse cutive white women (of European ethnic origin) volunteers attending th e antenatal clinic, with uncomplicated singleton pregnancies of at lea st 34 completed weeks' gestation. The participants had cardiotocograph y performed with an FHR monitor connected to a Sonicaid System 8002 co mputer. We studied the mean FHR, long-term FHR variation, short-term F HR variation, the number of accelerations, and the reactivity of the F HR. Results: The long-term FHR variation in centiles corrected for ges tational age, the duration in minutes of episodes of high FHR variatio n, the long-term FHR variation in beats pier minute during episode of high FHR variation, and the number of accelerations were significantly reduced in fetuses of black women compared with those in fetuses of w hite women (P = .007, P = .005, P = .009, and P = .006, respectively, Mann-Whitney U test). The fetuses of black women had a significantly h igher proportion of nonreactive traces (P = .009, Fisher exact test). However, there was no significant difference in the short-term FHR var iation between the two groups (P = .101). Conclusion: There is ant eth nic difference in FHR variation, with significantly reduced long-term variation in black. fetuses. (C) 1998 by The American College of Obste tricians and Gynecologists.