Maternal plasma HbF levels in pregnancy.

Abstract

Serial maternal serum hemoglobin F (HbF) levels were measured by radioimmunoassay in 23 normal pregnancies. The maternal HbF fraction remains within the normal range during the first trimester (mean + 2 S.D. = 0.15 + 0.13). After 15 weeks gestation, maternal HbF levels rise in some, but not all, pregnancies. In about 30% of the cases the HbF fraction remains within the range seen in adult men and non-pregnant women. Irregular rises in HbF were found in other pregnancies studied serially. The maternal HbF fraction may be an indicator of transplacental hemorrhage.