Lack of Association between Unexplained Elevated Maternal Serum Alpha Fetoprotein and/or Human Chorionic Gonadotropin and the Occurrence of Placental Thrombotic Lesions

ObjectiveTo investigate the significance of unexplained elevated maternal serum alpha fetoprotein (MSAFP) and/or human chorionic gonadotropin (HCG) on the occurrence of placental thrombotic changes.Study designBetween January 2007 to April 2009, placentas of all women who delivered and had unexplained elevated MSAFP and/or HCG (above 2 MOM) were sent to histological examination. Women were divided into 2 groups. Group A included women who had uneventful pregnancies and delivered at term. Group B included women with antepartum complications attributed to thrombosis. Women in both groups (A and B) had elevated MSAFP and/or HCG. Group C was a frequency matched group of women who had normal MSAFP and HCG levels with uneventful pregnancies and delivered at term.Main outcome measureIncidence of placental thrombotic lesions in each group.ResultsOf 9695 women who delivered during the study period there were 76 women with elevated MSAFP and or HCG, 48 in group A and 28 in Group B. Group C, included 30 women. The number of placentas in which any thrombotic lesion was identified was 22 (45.8%), 19 (67.9%) and 10 (33%) respectively. Changes differed significantly only between group B and C (p = 0.03). Although the rate of changes in group A was higher than in group C it did not reach statistical significance even when considering only women with two abnormal results (MSAFP and HCG) or when a cutoff of 2.5 MOM or more was set.ConclusionPlacental histopathological changes are associated with pregnancy complications and can only marginally be attributed to unexplained elevated MSAFP and/or HCG.