Lack of association between unexplained elevated maternal serum alpha fetoprotein and/or human chorionic gonadotropin and the occurrence of placental thrombotic lesions

Abstract

Objective: To 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 design: Between 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 measure: Incidence of placental thrombotic lesions in each group.

Results: Of 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.

Conclusion: Placental histopathological changes are associated with pregnancy complications and can only marginally be attributed to unexplained elevated MSAFP and/or HCG.