Correlation of ultrasound findings and biochemical markers in the second trimester of pregnancy in fetuses with trisomy 21.

Objective: The aim of the present study was to assess possible correlations between ultrasound findings and maternal serum biochemical ('triple test') markers among fetuses with trisomy 21 in the second trimester of pregnancy.

Methods: The study was a retrospective cohort study of 72 pregnancies affected by trisomy 21 who had a second trimester ultrasound and biochemical screen performed at a single center between 1990 and 1999. The biochemical screen consisted of alpha-fetoprotein (AFP), total beta human chorionic gonadotrophin (hCG) and estriol (uE(3)).