Chorionic villus sampling and the risk of adverse outcome in patients undergoing multifetal pregnancy reduction

Objective The objective of the study was to determine whether patients undergoing chorionic villus sampling (CVS) prior to MPR are at increased risk for adverse outcome compared to those who did not. Study Design We retrospectively identified multifetal pregnancy reduction (MPR) patients from an established database. Maternal demographic data were collected. Outcomes including complete pregnancy loss prior to 24 weeks' gestation, gestational age at delivery, and birthweight were analyzed. Results There was no significant difference in pregnancy loss between the 2 groups (CVS [4%] vs no CVS [7%], P = .098). When stratified by finishing number, there was a significantly lower loss rate in the singleton CVS group (2% vs 9%, P = .025) and no significant difference in reduced twins. There was no significant difference in the average gestational age of delivery or birthweight. Conclusion CVS prior to MPR does not increase the risk of pregnancy loss. Our data suggest that CVS prior to singleton reduction may decrease the risk of adverse outcome.