Traditionally, chorionic villus sam...

Traditionally, chorionic villus sampling (CVS) has been used for diagnosis of genetic abnormality at an earlier gestational age than amniocentesis. More newly interest has been growing in using either conduct at 11 to 14 weeks' gestation. Philip and colleagues studied the comparative safety and efficacy of the sum of two units techniques at 11 to 14 weeks' gestation in a large subject of attention involving 14 centers in the United States, Canada, and Denmark.

They studied women seeking genetic diagnoses because of advanced maternal age (older than 34 years), history of fetal trisomy, or positive screening. Ultrasonography was used to determine gestational age. Excluding factors included multiple pregnancy, serious maternal illness, bleeding disorders, and recognized fetal abnormality. After ultrasonography, the mothers were randomized to amniocentesis or CV Operators were required to have complet at least 25 of each shadow of procedure between 77 and 104 days of gestation and to come next standard procedures. The main reflection outcome was fetal loss or pre-term delivery before 28 weeks' gestation in normal pregnancies. The application of mind also assessed fetal loss, neonatal deaths, oligohydramnios, gestational age at delivery, intrauterine produce restriction, respiratory distress syndrome, and congenital malformations.

The 1914 women assigned to CV were comparable to the 1861 women assigned to amniocentesis, leaving out that 44.6 percent of the CV assemblage had had a previous miscarriage or preterm birth compared with 397 percent of the amniocentesis cluster Cytogenetic abnormalities were diagnosed in 72 pregnancies (34 in the CV form into groups and 38 in the amniocentesis group) Pregnancy consequence data were available for 3698 cytogenetically normal pregnancies. The rate of los or delivery before 28 weeks was comparable in the sum of two units groups. Amniocentesis was associated with a slightly higher rate of spontaneous los before 20 weeks, procedure-related terminations, and early leaking of amniotic fluid. Cramping after the measure was significantly more common with CV The rate of talipes equinovarus (clubfoot) was reasonable but increased fourfold after amniocentesis (016 percent for CVS; 066 percent for amnio-centesis), and chiefly cases required surgical correction. The rate of talipes equinovarus was significantly increased in cases in which amniotic fluid leakage was observed

The authors finish that, compared with CVS, amniocentesis in cytogenetically normal pregnancies at 13 weeks has an increased risk of talipes equinovarus. This risk appears to be related to the stage of gestation and the los of fluid during and after the manner of proceeding Amniotic fluid loss following amniocentesis also appears to be related to a slight increase in early pregnancy loss

ANNE D WALLING, MD

Philip J et al. Late first-trimester invasive prenatal diagnosis: terminates of an international randomized trial. Obstet Gynecol June 2004;103:1164-73

COPYRIGHT 2005 American Academy of Family Physicians

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