Complication rates after chorionic villus sampling and midtrimester amniocentesis: A 7-year national registry study

Purpose: To assess the complication rates following chorionic villus sampling (CVS) and midtrimester amniocentesis in Taiwan. Methods: This is a national registry-based cohort study from Taiwan. We included all women with singleton pregnancies who received either CVS (n = 1409) or midtrimester amniocentesis (n = 250,566) during 2006–2012. We assessed preterm premature rupture of membranes (PPROM), intrauterine fetal demise (IUFD), infection and spontaneous abortion (SA) that occurred within fourteen days after the procedures. We also assessed the risks of preterm delivery and miscarriage before 24 gestational weeks after amniocentesis. These complications were collected from the Genetic Disease Database of the Ministry of Health and Welfare, Taiwan National Birth Certificate Registry, and the Taiwan National Health Insurance Database. Pearson χ2 tests were used to compare the distributions between groups. Results: For patients who underwent midtrimester amniocentesis, the rates of PPROM, IUFD, infection and SA within fourteen days were 0.24%, 0.11%, 0.05%, and 0.05%, respectively. Women with a normal fetal karyotype had a preterm birth rate (<37 gestational weeks) of 9.38%. The miscarriage rate (<24 gestational weeks) was 0.68%, which was 0.22% higher than those who did not receive the invasive procedures (p < 0.0001). After CVS, the IUFD rate was 1.68%, and the SA rate within fourteen days was 0.77%. Conclusion: The use of our large cohort demonstrated that the procedure-related complication rates were comparable to recent review or meta-analysis. This dataset might facilitate counselling in women who consider invasive genetic diagnostic procedures. Keywords: Amniocentesis, Chorionic villus sampling, Infection, Miscarriage, Preterm premature rupture of membranes