Depressed serum levels of human placental lactogen in first trimester vaginal bleeding.

Background: It has previously been shown that serum levels of pregnancy-associated plasma protein A (PAPP-A) are depressed in patients with early pregnancy bleeding and a live gestation. We examined whether human placental lactogen (hPL) levels show a similar pattern.
Method: Prospective study in the 8th-14th gestational week comparing serum levels in 69 women with early pregnancy bleeding with those in 93 control pregnancies.
Results: Serum levels of hPL were significantly depressed in women with early pregnancy bleeding (p < 0.0001).
Conclusions: The findings suggest a primary affection of the placenta in early pregnancy bleeding.