Is Amniocentesis after CVS Risky?

Area of Science:

• Maternal-Fetal Medicine
• Prenatal Diagnostics
• Reproductive Genetics

Background:

• Approximately 2% of women undergoing chorionic villi sampling (CVS) require a subsequent amniocentesis.
• Reasons for a second procedure include placental mosaicism, sampling errors, or laboratory issues.
• The obstetric outcomes of women undergoing both CVS and amniocentesis are not well-established.

Purpose of the Study:

• To compare obstetric outcomes in women who underwent both CVS and amniocentesis versus those who underwent CVS alone.
• To assess the safety and impact of a second invasive procedure on pregnancy outcomes.

Main Methods:

• Retrospective case-control study (2010-2020) of singleton pregnancies.
• Compared 66 women who had CVS followed by amniocentesis with 132 controls who had CVS alone.
• Matched for maternal age and year of pregnancy; excluded early pregnancy loss and terminations.

Main Results:

• No significant differences in pregnancy loss or stillbirth between the two groups.
• Women undergoing both procedures delivered at similar gestational ages and birthweights.
• Amniocentesis was performed for placental mosaicism (44%), sampling/lab issues (33%), or further testing (23%).

Conclusions:

• Women requiring amniocentesis after CVS can be reassured about adverse outcomes.
• The study suggests that a second invasive procedure does not increase risks.
• Larger studies may be needed to detect rare adverse event differences.