Acute hemodynamic effects induced by chorionic villus sampling: a preliminary investigation.

Objective: Our purpose was to evaluate the effects of chorionic villus sampling on the fetal heart rate, the fetal umbilical artery pulsatility index, and the maternal arcuate artery resistance index.
Study Design: M-mode fetal heart rate, pulsed Doppler fetal umbilical artery pulsatility index, and maternal arcuate artery resistance index measurements were obtained before and immediately after chorionic villus sampling in 50 patients and were compared with 50 procedure-free, gestational age--matched controls. Comparisons within groups were performed with paired T tests and mean changes between groups with two-sample T tests, and variance comparisons between groups were performed with F tests.
Results: The mean changes (SD) in fetal heart rate, umbilical artery pulsatility index, and arcuate artery resistance index in patients undergoing chorionic villus sampling and in controls were not statistically different from zero or from each other. However, the variance around the mean fetal heart rate change was 17.1 times larger in the chorionic villus sampling group than the control group (F 17.1, degrees of freedom 49,49, p < 0.0001), and the variance around the mean pulsatility index change was 2.7 times larger in the chorionic villus sampling group than in the control group (F 2.7, degrees of freedom 49,49, p = 0.0007). There was no significant difference in mean resistance index change or variance around the mean resistance index change between groups.
Conclusion: Chorionic villus sampling induces significant but unpredictable fluctuations in fetal heart rate and umbilical artery pulsatility index but does not affect maternal arcuate artery resistance index.