Albumin binding of MADDS--a measure of bilirubin binding--in women during pregnancy and after delivery and in their infants.

The purpose of this study was to investigate the binding potential of MADDS (monoacetyldiaminodiphenyl sulphone) to albumin, a measure for binding of unconjugated bilirubin, in healthy women during pregnancy, during and after delivery, and in their infants. The serum concentrations of unconjugated bilirubin, reserve albumin for binding of MADDS and total albumin were measured in: (a) 21 non-pregnant women; (b) 16 pregnant women in the 16th-24th, 28th-32nd, and 36th-38th gestational weeks, and at the time of delivery from both mother and infant; and (c) 15 women at the time of delivery, and 24 and 72 hours after delivery. The bilirubin concentrations did not change during pregnancy or at delivery and were very small compared with the concentrations of reserve albumin for binding of MADDS and total albumin. Therefore, the ratio of reserve albumin to total albumin was an expression of the binding potential of the albumin for MADDS in women. During pregnancy, the reserve albumin decreased equal to total albumin, so that the ratio was not significantly changed (p greater than 0.05). In contrast, at delivery the reserve albumin was significantly lower (p less than 0.01) than in the 36th-38th gestational weeks, without any significant difference in total albumin, i.e. the ratio was significantly lower than during pregnancy (p less than 0.01). During the first 3 days after delivery the reserve albumin increased significantly (p less than 0.05), also without any significant change in total albumin, so that the ratio increased significantly (p less than 0.05) and was normalized. The binding potential for MADDS to albumin in newborn infants was even lower than that of their mothers. Since the binding-potential is reduced in both mother and infant at delivery, a relation is suggested.