P20.10: Risk of fetal loss in pregnancies undergoing mid‐trimester amniocentesis after inconclusive chorionic villus sampling

The purpose of this study was to evaluate the fetal loss rate in pregnancies that undergo amniocentesis after inconclusive chorionic villus sampling. This was a multicentric retrospective cohort study of 278 patients (275 singleton pregnancies and three dichorionic twin pregnancies) in which both chorionic villus sampling at 11–13 weeks' gestation and amniocentesis at 16–22 weeks were performed. Amniocentesis was performed because of placental mosaicism (93.6%), failure of direct/semi-direct preparation of trophoblastic cells (3.2%), or targeted genetic testing after the diagnosis of an anomaly in the second trimester (3.2%). There were no fetal losses prior to 23 weeks gestation. Two intrauterine demises (including one fetus with multiple anomalies and growth restriction) in the third trimester were recorded. Patients undergoing mid-trimester amniocentesis because of an inconclusive result of chorionic villus sampling can be reasonably reassured that the risk of miscarriage following the procedure is very small. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.