EXPERIENCE WITH 1251 TRANSCERVICAL CHORIONIC VILLUS SAMPLINGS PERFORMED IN THE FIRST TRIMESTER BY A SINGLE TEAM OF OPERATORS

Objective: We report our experience with 1251 chorionic villus samplin gs (CVS) performed by a single team of operators. Study design: From A pril 1984 through August 1993, 1251 CVS were performed in 1236 pregnan cies. The transcervical route was used in the vast majority and the sa mpling was performed during the 9th through 13th weeks of gestation in 1193 cases (96%). Follow-up was ensured to tabulate the pregnancy-rel ated complications and fetal loss rate until 28 weeks' gestation. Preg nancy outcome was documented for all but 36 women (3%). Results: Most of the tests (72% - 891/1236 pregnancies) were performed for advanced maternal age (greater than or equal to 35 years). The percentage of ea ch indication remained relatively stable, around 90% for chromosomal i ndications and between 8 and 11% for DNA studies. Samples adequate for diagnosis were obtained in one or two sessions in 1179 pregnancies (9 5%). 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 delive ries (4.6%) and of small for gestational age were comparable to the ge neral uninstrumented population. Conclusion: CVS is a safe and effecti ve mode of antenatal diagnosis when performed by a single team of expe rienced operators.