Experience with 1251 transcervical chorionic villus samplings performed in the first trimester by a single team of...

We report our experience with 1251 chorionic villus samplings (CVS) performed by a single team of operators.

From April 1984 through August 1993, 1251 CVS were performed in 1236 pregnancies. The transcervical route was used in the vast majority and the sampling was performed during the 9th through 13th weeks of gestation in 1193 cases (96%). Follow-up was ensured to tabulate the pregnancy-related complications and fetal loss rate until 28 weeks' gestation. Pregnancy outcome was documented for all but 36 women (3%).

Most of the tests (72%-891/1236 pregnancies) were performed for advanced maternal age (> or = 35 years). The percentage of each indication remained relatively stable, around 90% for chromosomal indications and between 8 and 11% for DNA studies. Samples adequate for diagnosis were obtained in one or two sessions in 1179 pregnancies (95%). The rate of spontaneous abortion possibly related to CVS was 2.5% (28/1092). Mosaicism confined to the placenta was found in 23 cases (1.8%). The pregnancy outcome was known in 1098 pregnancies. There were 10 perinatal losses (0.9%) and nine congenital malformations (0.8%). No transverse limb defects were observed. The rate of premature deliveries (4.6%) and of small for gestational age were comparable to the general uninstrumented population.

CVS is a safe and effective mode of antenatal diagnosis when performed by a single team of experienced operators.