A number of studies have shown a relationship between chorionic villus sampling (CVS) and an increased risk of hypertensive disorders in pregnancy. The present retrospective study was performed to examine whether CVS has a different risk of hypertensive complications compared with second-trimester genetic amniocentesis among low-risk women.
Data were reviewed from pregnant women who underwent CVS or amniocentesis between 1998 and 2011. All study women had either transabdominal CVS at 10 to 13 weeks’ gestation or amniocentesis at 17 to 21 weeks; all procedures were performed with ultrasonographic guidance. Maternal demographics and obstetric data were recorded. Standard parameters for diagnosis of preeclampsia, proteinuria, and gestational were applied.
A total of 3243 women who underwent CVS and 6875 who underwent amniocentesis were included in the analysis. The demographics of the 2 groups were similar except that those in the amniocentesis group were significantly older (35.5 ± 4.5 vs 30.0 ± 5.9 years; P < 0.001). Of the women having CVS, 2694 (83.1%) did so because both parents had the β-thalassemia trait; the other 549 women had it for fetal karyotyping. Most women (6378; 92.8%) had amniocentesis for fetal karyotyping because of advanced maternal age. In total, 237 (2.3%) developed hypertensive disorders during their pregnancy. The rates for preeclampsia were 2.4% and 0.8% in the CVS and amniocentesis groups, respectively (P < 0.001). The respective rates for gestational hypertension were 1.3% and 0.9% (P = 0.036), and those for total hypertensive complications were 3.8% and 1.7%, respectively (P < 0.001). On multiple logistic regression analysis, compared with the amniocentesis group, women in the CVS group had 2.89-, 1.50-, and 2.21-fold greater likelihoods of having preeclampsia, gestational hypertension, and preeclampsia or gestational hypertension, respectively.
These results indicate that parturients having CVS have a significantly higher risk of developing hypertensive disorders compared with those undergoing amniocentesis and support the theory that first-trimester placental disruption after CVS can subsequently cause abnormal placental function, leading to the development of preeclampsia or gestational hypertension. A well-designed prospective study is needed to fully assess the possible relationship between CVS and hypertensive complications in pregnancy.