Transabdominal chorionic villus sampling.

The first 100 patients undergoing first trimester transabdominal chorionic villus sampling (placental biopsy) in our hospital are reviewed. At the time of follow up 24 patients had delivered, 68 pregnancies were at 24 weeks or more and progressing normally, 7 pregnancies were terminated and there was only 1 spontaneous miscarriage. The advantages of the transabdominal approach are discussed.

Transabdominal chorion villus sampling: a safe and reliable procedure.

A complete follow-up of the first 578 patients undergoing transabdominal chorion villus sampling (TACVS) in our combined practices was undertaken to determine the pregnancy loss rate. Factors contributing to losses and the problems incurred in achieving a clinically relevant result were also examined. It was found that increasing experience led to fewer procedural difficulties but that there persisted a higher problem rate in those women with a retroverted uterus. In 98.1% of patients an adequate volume of tissue was obtained and in 95.5% a clinically relevant result was achieved. This second figure rose to 96.3% in the latter part of the study. There was a total fetal loss rate of 2%, with only 0.5% (3 patients) having a missed abortion within 4 weeks of the procedure. It is concluded that TACVS is a reliable procedure with a high level of safety.

Correlation between nuchal thickness and abnormal karyotype in first trimester fetuses.

OBJECTIVE: To evaluate the accuracy of ultrasound measurement of nuchal thickness in first trimester fetuses for predicting fetal karyotype. DESIGN: A prospective study of the nuchal thickness of fetuses measured during an ultrasound examination in all women undergoing first trimester chorionic villus sampling (CVS). SETTING: Two major public hospitals and two associated private practices between 7 September 1993 and 6 September 1994. PARTICIPANTS: Pregnant women with various indications for CVS (in 82% because of maternal age). RESULTS: 1306 women underwent CVS, including 11 with twin pregnancies: 1317 fetuses were tested. Karyotype results were obtained for 1312 fetuses: 41 (3.1%) had an abnormal karyotype, and 20 of these (49%) had a nuchal thickness measurement of 3 mm or more, compared with 44 (3.5%) of the 1271 fetuses with a normal karyotype. Of the 21 fetuses shown to have trisomy 21, 12 would have been detected if a nuchal thickness of 3 mm or more had been used as an indicator, giving a sensitivity of 57%. Nuchal thickness measurements of 1 or 2 mm excluded trisomy 21 with a negative predictive value of 99.3%. Fetuses with moderate nuchal thickening, normal karyotype and no other problems noted on the initial ultrasound scan had neonatal outcomes similar to those in the general obstetric population. CONCLUSION: Nuchal thickening in the first trimester (10 weeks on) of pregnancy in a high risk population is a powerful indicator of increased risk of aneuploidy.