Accuracy of single measurements of pregnancy-associated plasma protein-A, human chorionic gonadotropin and progesterone in the diagnosis of early pregnancy failure.

Background: Circulating human chorionic gonadotropin (hCG) and progesterone are commonly used as markers of abnormal pregnancies. Previous studies have shown that pregnancy-associated plasma protein-A (PAPP-A) was also depressed in extrauterine pregnancies (EUP). Previously, PAPP-A was measured with polyclonal antibodies which were later shown to recognise also the pro-form of major basic protein (pro-MBP).