We report three cases in which triploidy (69,XXX) was detected by amniocentesis performed for very low maternal serum human chorionic gonadotropin levels. All three cases also had low maternal serum unconjugated estriol levels. We suggest placental insufficiency as the cause of the very low human chorionic gonadotropin because of histologic observations and because a known marker for placental insufficiency, estriol, was also very low.
- low maternal serum unconjugated estriol
- maternal serum human chorionic gonadotropin
- placental insufficiency