Placental protein 10 (PP10) in normal pregnancy and cholestasis of pregnancy.

The circulating concentrations of placental protein 10 (PP10) were measured by radioimmunoassay in 288 women with normal pregnancy and ten women (55 samples) with cholestasis of pregnancy. Serum PP10 levels were not affected by changes in incubation and storage temperature, and no diurnal variation was observed. The highest PP10 levels (36-85 micrograms/l) in normal pregnancy were found at 34 weeks. The postpartum decline of serum PP10 concentration corresponded to an average half-life of 18 h. In cholestasis of pregnancy at 32-39 weeks, the serum PP10 levels were found to be lower than normal. Negative correlation was observed between aminotransferase and PP10 levels in serum and between the bile acid levels and the PP10 concentration. These results suggest that the severity of maternal liver disorder is reflected in the circulating PP10 concentration.