Placental insufficiency as a possible cause of low maternal serum human chorionic gonadotropin and low maternal serum unconjugated estriol levels in triploidy

Screening for triploidy by fetal nuchal translucency and maternal serum free ?-hCG and PAPP-A at 10-14 weeks of gestation

“…Previous biochemical studies in triploid pregnancies during the second trimester have also shown that maternal serum hCG can either be low or high. Thus, ®ve studies on a total of 10 triploid pregnancies reported very low levels of total hCG and unconjugated oestriol (Bogart et al, 1989;Kohn et al, 1991;Mason et al, 1992;Fejgin et al, 1992;. Two studies on a total of seven cases of triploidy reported that in some pregnancies total hCG can be very low and in others it can be very high (Oyer and Canick, 1992;Muller et al, 1993).…”

Steroid sulphatase deficiency is the major cause of extremely low oestriol production at mid-pregnancy: a urinary steroid assay for the discrimination of steroid sulphatase deficiency from other causes

“…Chromosomal causes of reduced oestriol include autosomal trisomy (Canick et al, 1990), Turner's syndrome Wenstrom et al, 1994) and triploidy (Fejgin et al, 1992). All of the above give rise to a more modest reduction in serum oestriol levels and are unlikely to be confused with steroid sulphatase deficiency by maternal urine steroid analysis.…”

Gonadal Pathology in Triploidy

“…Although the role of hCG in normal sex differentiation is unclear, it may regulate production of testosterone by the testis [35,36]. In digynic triploidy, the placenta is abnormally small [2,3] and the hCG and estriol levels are markedly decreased [37][38][39][40]. With abnormally low levels of hCG, Leydig cell production of testosterone may be compromised, leading to defective virilization of external genitalia.…”