Chorionic villus sampling after the first trimester.

Background: The purpose of this article was to evaluate the association between late CVS (placental biopsy) and complications between sampling and delivery. Methods: Late chorionic villus sampling under ultrasound guidance was carried out in 3000 (85.7%) cases in the second trimester and 500 (14.3%) cases in the third trimester of pregnancy. Out of 3500 late CVS, 710 (20.3%) were performed because of suspicious ultrasonographic findings. In the 500 patients between 13 and 16 weeks of gestation color, Doppler was used to investigate the uteroplacental and fetal vessels before and after late chorionic villus sampling. Results: In 30 patients (0.85%), complications between sampling and delivery were found. There were only 11 (0.31%) spontaneous abortions four to six weeks after late chorionic villus sampling. We found 166 (4.74%) chromosomal abnormalities. In the group with suspicious ultrasonic findings (710 cases), we found significant oligohydramnios in 314 (44.2%) and significant polyhydramnios in 155 (21.8%), and 110 (15.5%) had chromosomal abnormalities. Among the 166 patients with chromosomal abnormalities, ultrasonographic findings in 90 (54.2%) were detected after 20th week of pregnancy. There were no significant differences in mean pulsatility indices between uteroplacental and fetal vessels before and after late chorionic villus sampling. Preliminary data for 25 trisomic fetuses indicate an abnormally increased umbilical PI and abnormally decreased middle cerebral artery PI. Conclusions: Late CVS is a safe method of prenatal diagnosis for high-risk couples and does not significantly affect the outcome of pregnancy. [ABSTRACT FROM AUTHOR]