The placental transfer and concentration difference in maternal and neonatal serum uric acid at parturition: comparison of normal pregnancies and gestosis.

The maternal uric acid (MUA) and neonatal uric acid (NUA) levels were measured simultaneously at parturition in three groups of pregnancies: group I - 83 cases of normal pregnancies, group II - 7 cases of mild gestosis and group III - 12 cases of severe gestosis, totaling 102 cases. Umbilical venous blood samples were taken in all of the cases. Maternal venous blood samples were obtained from 69 patients in group I, 6 cases in group II, and 12 cases in group III. The correlation coefficients of MUA and NUA values were 0.90, 0.91, and 0.95 (all p less than 0.01) in the three groups, respectively, and 0.93 in total series (p less than 0.0001). The high correlation and minimal concentration difference between MUA and NUA in either normal or gestosis suggested free transfer of uric acid via placenta in both directions. Moreover, not only MUA but also NUA levels were significantly different among normal and gestosis groups, and both MUA and NUA showed higher levels in accordance with the severity of gestosis. Both MUA and NUA had negative correlation with birth weight (BW), one-minute apgar score (AS-1) and five-minute apgar score (AS-5). It implied that the uric acid levels at parturition might provide as a reference index for fetal outcome in pregnancy with gestosis.