OC09.02: Complications and outcome of invasive prenatal diagnosis in twin pregnancies

Abstract

Objectives: To report our experience on the complications and outcome of twin pregnancies undergoing amniocentesis or chorionic villus sampling (CVS) for prenatal diagnosis. Methods: Retrospective review of all cases of twin pregnancies that underwent invasive prenatal diagnosis at our Institution in the last 10 years. Chorionicity and indication for invasive testing were retrieved from the clinical notes. The following outcomes were analysed: fetal loss within 4 weeks from the procedure and <24 weeks' gestation; preterm premature rupture of membranes (PPROM) within 4 weeks from the procedure and <34 weeks' gestation; spontaneous preterm delivery (PTD) <32 weeks of gestation. Results: A total of 267 twin pregnancies underwent invasive prenatal diagnosis during the study period, 212 dichorionic diamniotic and 55 monochorionic diamniotic. Amniocentesis was the most frequent procedure in both groups. Indications for invasive testing, type of procedure used, and pregnancy outcomes are described in Table 1 and reported with their 95% confidence intervals. Conclusions: We observed a fetal loss rate <24 weeks of 1.5% (95% CI, 0.3â€4.3). As expected, monochorionic pregnancies had a higher incidence of adverse pregnancy outcome. Dichorionic twins (n = 212)Monochorionic twins (n = 55)Total(n = 267) Indications -increased NT 7% (3.8-11.8) 15% (7.4-25.7) 9% (5.9-13.4) -structural abnormality 11% (6.8-16.3) 19% (10.8-30.9) 13% (9.2-18) -maternal age 78% (71.6-84) 63% (50-74.2) 74% (68-79) -other 4% (1.5- 7.7) 3% (0.4-10.4) 4% (1.7-6.7) Amniocentesis 87% (81.2-91.5) 84.8% (73.9-82.5) 87% (83-91) CVS 13.0% (8.5-18.8) 15.2% (7.5-26) 13.0% (10-19) Fetal loss within 4 weeks 0.7% (0-3.8) 0% (0-6.5) 0.5% (0-2.7) Fetal loss <24 weeks 0.7% (0-3.8) 3.4% (0.4-11.7) 1.5% (0.3-4.3) PPROM within 4 weeks 2.1% (0.4-6) 0% (0-6.5) 1.5% (0.3-4.3) PPROM <34 weeks 4.9% (2-9.8) 3.4% (0.4-11.7) 4.4% (2- 8.2) Spont PTD <32 weeks 4.3% (1.6-9) 10.2% (3.8-20.8) 6.0% (3.1-0.2).