Outcome after second-trimester amniocentesis and first-trimester chorionic villus sampling for prenatal diagnosis in multiple gestations.

PURPOSE: The purpose of this study was to classify pregnancy loss and fetal loss as well as the influence of maternal risk factors in multiple pregnancies. METHODS AND MATERIALS: Details of the procedure and pregnancy outcome of all patients were extracted from the clinical audit database of two tertiary centers. The files were collected in the time from January 1993 to May 2011.  The procedure-related pregnancy and fetal loss rate was classified as all unplanned abortions without important fetal abnormalities or obstetric complications within 14 days after AC and CVS. RESULTS: We had a total number of 288 multiple pregnancies with a total of 637 fetuses. After the exclusion of 112 pregnancies with abnormal karyotype or fetal abnormalities detected by ultrasound as well as cases of selective feticide, repeated invasive procedures and monochorionic-monoamniotic pregnancies, 176 pregnancies and 380 fetuses were left for final analysis. Overall 132 amniocenteses and 44 chorionic villous sampling procedures were performed. The total pregnancy loss rate was 8.0 % (14/176), 6.1 % (n = 8) for amniocentesis and 13.6 % (n = 6) for CVS.  The procedure-related pregnancy loss rate was 3.4 %, 2.3 % after amniocentesis (3 cases) and 6.8 % after CVS (3 cases). There was no statistical significance between the two procedures (p = 0.15). CONCLUSION: The procedure-related loss rate of 3.4 % can be compared to the rates in the literature. The higher loss rates in multiple pregnancies than in singleton pregnancies have to be discussed when counseling parents.

Fetal loss rate and associated risk factors after amniocentesis, chorionic villus sampling and fetal blood sampling.

PURPOSE: To assess the total and procedure-related fetal loss rate and associated risk factors following amniocentesis (AC), chorionic villus sampling (CVS) and fetal blood sampling (FBS). MATERIALS AND METHODS: We performed a retrospective analysis of patients with invasive diagnostics from 1993 to 2011 in two tertiary referral centers. We aimed to classify pregnancy loss after an invasive procedure and included the time after the invasive procedure and the result of targeted ultrasound/karyotype analysis in the analysis. Fetal losses occurring within two weeks after an invasive procedure were classified as procedure-related. RESULTS: After excluding 1553 pregnancies with abnormal karyotype, fetal malformations and multiple insertions, 6256 cases were retrieved for final analysis. The total fetal loss rate was 1.5 %. The procedure-related fetal loss rate was 0.4 % for AC, 1.1 % for CVS and 0.4 % for FBS. Maternal vaginal bleeding in the first trimester was significantly associated with an increased procedure-related fetal loss rate (p= 0.008). The number of invasive procedures declined during the study period with increasing numbers of CVS in the first trimester. CONCLUSION: In our population the procedure-related fetal loss rate was 0.4 % after AC and 1.1 % and 0.4 % after CVS and FBS, respectively. Different gestational ages at the time of invasive procedures might account in part for those differences. Vaginal bleeding during the first trimester is associated with increased procedure-related fetal loss. Overall, declining numbers of invasive procedures are the result of changing attitudes toward invasive procedures and more sophisticated noninvasive prenatal screening programs over the last 20 years.