Is Amniocentesis after CVS Risky?
Academic Article
Overview
abstract
OBJECTIVE: Approximately 2% of women who undergo CVS will subsequently undergo amniocentesis due to placental mosaicism or sampling/laboratory issues. Our objective was to compare obstetric outcomes in women who underwent both procedures with those who had CVS alone. STUDY DESIGN: Retrospective case-control study of patients with singleton pregnancies undergoing invasive testing from 2010-2020. All women who underwent CVS followed by amniocentesis were compared to a control group who underwent CVS alone matched (2:1) for age and year of pregnancy. Women with pregnancy loss at <16 weeks were excluded from the control group. Pregnancies terminated for genetic abnormalities were excluded. Obstetric outcomes were compared between cases and controls. Student t test and Fisher's exact test were used for statistical comparison. RESULTS: During the study period 2539 women underwent CVS, and 66 (2.6%) subsequently underwent amniocentesis. The 66 cases were compared to 132 age-matched controls who underwent CVS alone. Mean maternal age was 36.8 ± 3.4-yrs, and 43% of women were nulliparous. Amniocentesis was performed due to sampling or laboratory issues in 33% of cases, placental mosaicism in 44%, and further diagnostic testing in 23%. There were no pregnancy losses or stillbirths in either group. Those who had two invasive procedures delivered at similar gestational ages and birthweights, and did not have higher rates of adverse outcomes compared to those who underwent CVS alone. CONCLUSION: Patients considering CVS who are concerned about the possibility that a second invasive procedure could be required should be reassured that this does not appear to be associated with higher rates of adverse outcomes. Due to study size, we cannot exclude the possibility of small differences in uncommon outcomes, such as pregnancy loss or stillbirth.
