INCREASED LEVEL OF 2ND TRIMESTER MATERNAL SERUM CHORIONIC-GONADOTROPIN IN PREGNANCY WITH A FETUS AFFECTED BY HOMOZYGOUS ALPHA-THALASSEMIA-1

With enzyme immunoassay, maternal serum chorionic gonadotropin (MShCG) level was determined in 58 pregnancies affected with fetal homozygous alpha-thalassemia 1. In 40 pregnancies with a gestational age of 10 t o 14 weeks, 8 (20%) had an MShCG level above 2.5 multiples of the medi an (MoM); while in the other 18 pregnancies with a gestational age of 15 to 23 weeks, 14 (78 %) had a level above 2.5 MoMs and none had a le vel below the median. Homozygous alpha-thalassemia 1 of the fetus was associated with an elevated MShCG. Therefore in second-trimester scree ning for Down's syndrome by measurement of MShCG, homozygous alpha-tha lassemia 1 should also be considered if elevated MShCG levels are foun d.