Which is the best placental function test? A comparison of placental lactogen and unconjugated oestriol in the prediction of intrauterine growth retardation.

Serum placental lactogen (hPL) and unconjugated oestriol (E3) levels were measured in 392 women at weekly intervals from 36-40 wk gestation. The levels of both hPL and E3 were reduced in subjects delivering a growth-retarded child. The clinical significance of this observation was similar for the two compounds, with a marginal advantage to hPL. There was a higher incidence of falling levels of hPL and E3 in cases of growth retardation but the finding had very little predictive value in an individual patient.