Hyperhomocysteinemia: a risk factor for placental abruption or infarction.

OBJECTIVE To establish the prevalence of hyperhomocysteinemia in women with placental abruption or infarction. DESIGN Forty-six women with normal pregnancy outcome (controls) and 84 women with placental abruption or infarction (study group) were selected, and studied in the non-pregnant state. Homocysteine metabolism was investigated by a standardized oral methionine loading test. Hyperhomocysteinemia was defined as a concentration of fasting and/or postmethionine plasma homocysteine exceeding the estimated 97.5 percentile level of the controls. In the fasting state, the vitamin status was investigated by the measurement of serum and red cell folate, serum vitamin B12, and whole blood pyridoxal-5'-phosphate (PLP, an active form of vitamin B6). RESULTS Hyperhomocysteinemia was diagnosed in four controls (9%) and 26 women of the study group (31%, P < 0.05). The median concentrations of the vitamins studied were significantly lower in women of the study group as compared to the controls, except for red cell folate, where the median concentration was comparable in both groups. The median concentration of fasting plasma homocysteine, unlike post-methionine plasma homocysteine, was significantly higher in women who experienced placental abruption or infarction in their first pregnancy than in women who had the same event after one or more uncomplicated pregnancies. CONCLUSION Hyperhomocysteinemia is associated with placental abruption or infarction.