Résumé
Hyperglycosylated human ehorionic gonadotrophin [HhCG] also known as invasive trophoblast antigen [ITA] is a new test. It specifically detects a unique oligosaccharide variant of hCG associated with Down syndrome pregnancies. We evaluated this test diagnosis through confirmatory studies. HhCG was measured by ELISA technique using commercial kit of Nunc-Immunolab-l Fisher Scientific [Larry 2001].In urine samples from women undergoing amniocentesis for advanced maternal age concerns at 6-12 weeks of gestation. 908 with normal karyotyping and 30 Down syndrome fetuses [28-45 years old]. As confirmation 36 pregnant women over 45 years old non karyotyped. 33 delivered normal babies and 3 delivered Down babies. The mean HhCG value was 7.3-7.7 folds higher in Down syndrome at 6-8 weeks gestation and 7.8-9.5 folds at 9-12 weeks gestation for women 28-45 years old. While it was 6.7 folds higher at 6-8 weeks gestation and 9.8 folds higher at 9-12 weeks gestation for women over 45 years old with Down syndrome babies. Urinary HhCG could be a new predictive non invasive marker for Down syndrome screening in the 1[st] trimester when 8-9 folds higher than normal on adding the advanced maternal-age risk factor. It can be an alternative to amniocentesis, this was a small study, thus the best clinical value of test can be established in large trials