Blood ascorbic acid and histamine levels in patients with placental bleeding.

Concentrations of histamine and total ascorbic acid (L-ascorbic acid plus dehydroascorbic acid) in the antecubital vein blood of women in abruptio placentae (normally situated placentae) and placenta praevia have been measured. The results show that blood ascorbic acid in abruptio placentae is significantly (P less than 0.05) lower than the values found in placenta praevia. This may reflect impaired absorption and/or increased breakdown of ascorbic acid in abruptio placentae. Histamine levels in the two conditions are similar to one another.