Amniocentesis and Risk of Fetal Loss in Dichorionic-Diamniotic Twin Pregnancy: A Case-Control Study

Objective: There is a paucity of data regarding the risk of fetal loss due to invasive prenatal diagnosis in twins. The aim of the present study is to assess the rate of amniocentesis-related fetal loss in uncomplicated dichorionic-diamniotic (DCDA) twin pregnancies. Methods: Retrospective observational case-control study. DCDA twin pregnancies undergoing amniocentesis between January 2010 and December 2023 formed the case group. The control group comprised counterparts who did not undergo amniocentesis. The primary outcome of the study was procedure-related fetal loss. Secondary outcomes were miscarriage rate, overall fetal loss and gestational age at birth. Results: Our dataset included 220 and 662 women in the case and control groups, respectively. No difference in the primary outcome was found: procedure-related fetal loss of one fetus was 0.9% in the case group and 1.1% in the control group, and of both fetuses it was 0.5% in both groups (p = 0.982). No difference was found in secondary outcomes: the fetal loss rate of one fetus was 1.8% in the case group and 2.1% in the control group, while that of both fetuses it was 0.5% and 0.8% respectively (p = 0.853). Multivariate analysis confirmed the nonsignificant effect of amniocentesis on the risk of fetal loss. Conclusion: Amniocentesis does not seem to increase the risk of fetal loss in uncomplicated DCDA twin pregnancies above the baseline risk of loss among twin gestations.