Does first trimester chorionic villus sampling affect fetal and/or placental blood flow seven to ten weeks later?

Objective: To assess whether patients undergoing first trimester chorionic villus sampling have a significantly different fetal umbilical artery pulsatility index and maternal arcuate artery resistance index 7-10 weeks later. Methods: We conducted a retrospective cohort study identifying the control group by identifying n = 368 sequential patients undergoing fetal umbilical artery Doppler studies between 16 and 20 weeks gestation inclusive at the Antenatal Testing Unit at Pennsylvania Hospital. To be included as the control the Doppler study had to be performed on a singleton pregnancy with an indication of advanced maternal age, normal maternal serum alpha-fetoprotein, and with no entry in the chorionic villus sampling database. The study group comprised 56 patients who had chorionic villus sampling performed between 9 and 12 weeks gestation because of advanced maternal age. Detailed ultrasound and fetal umbilical artery pulsatility index were obtained between 16 and 20 weeks gestation in both groups of patients. A subset of patients was identified who had measurements of maternal arcuate artery resistance indices in addition to fetal umbilical artery pulsatility indices. The control group comprised n = 151 sequential patients and the study group comprised n = 26 patients. Results: The mean (SD) fetal umbilical artery pulsatility indices in the chorionic villus sampling and control groups were 1.34 (0.20) and 1.41 (0.27), respectively. These mean values did not significantly differ (Welch's T = -0.64, df 86.7, P = 0.52). The mean (SD) maternal arcuate artery resistance indices in the CVS and control groups were 0.38 (0.10) and 0.37 (0.09), respectively. These mean values also did not significantly differ (pooled T = 0.38, df 175, P = 0.70). Conclusion: First trimester chorionic villus sampling does not affect the fetal umbilical artery pulsatility index and maternal arcuate artery resistance index 7-10 weeks later.