SCREENING FOR DOWN-SYNDROME USING URINE HCG FREE BETA-SUBUNIT IN THE 2ND-TRIMESTER OF PREGNANCY

Human chorionic gonadotropin (hCG) free beta-subunit levels were deter mined in 709 control and 13 Down syndrome urine samples from the secon d trimester of pregnancy. Results were normalized to urine creatinine concentration and converted to multiples of the unaffected pregnancy m edium (MOM). The concentration of free beta-subunit in Down syndrome c ases was 3.9 MOM. Seven of 13 Down syndrome pregnancies (54 per cent) had free beta-subunit levels at or above the 95th centile of unaffecte d pregnancies. Urine free beta-subunit may potentially be useful as a screening test for Down syndrome. (C) 1997 by John Wiley & Sons, Ltd.