Transabdominal Chorionic Villus Sampling

EDITORIAL COMMENT: Chorion villus sampling is likely to replace genetic amniocentes'is in many patients mainly because the procedure can be performed so much earlier in pregnancy (8–12 weeks rather than 16–17 weeks) when the safety of termination of pregnancy, should this be required, is greater. Most recent reports state that the risk of genetic amniocentesis is less than 1 %, but readers may find it difficult to believe that the loss rate following chorion villus sampling is as low as 2–3% when the spontaneous abortion rate is about treble this figure in patients with apparently normal pregnancies who book for confinement with their obstetrician at about the time that chorionic villus sampling is performed. The important point to note is that, many patients with apparently normal pregnancies clinically at 8–10 weeks have a missed abortion (blighted ovum) which would not be diagnosed unless ultrasonography and/or estimation of urinary or plasma oestrogen and pregnanediol were performed. Summary: 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.