Placental alkaline phosphatase compared with human placental lactogen and oestriol in high-risk pregnancies.

Serum levels of placental alkaline phosphatase (PLAP), human placental lactogen (HPL) and oestriol (E3) were investigated in 33 women with high-risk pregnancies. In pregnancies complicated by intrauterine growth retardation (IUGR) low PLAP values were constantly recorded. HPL values showed a similar pattern while E3 levels were between normal mean and the lower limit of -2 SD. A clear differentiation between IUGR and pre-eclampsia was achieved by the simultaneous determination of PLAP and HPL. It is suggested that PLAP determinations may be more informative than E3 to detect placental insufficiency.