Maternal serum placental protein 13 at 11-13 weeks of gestation in preeclampsia.

OBJECTIVE To examine the potential value of maternal serum concentration of placental protein 13 (PP13) at 11-13 weeks' gestation in screening for preeclampsia (PE). METHODS Serum PP13, PAPP-A and uterine artery pulsatility index (PI) were determined in a case-control study of 208 cases that developed PE including 48 that required delivery before 34 weeks (early-PE) and 416 unaffected controls. RESULTS Serum PP13 levels, expressed as multiples of the median (MoM) in the unaffected group, were significantly reduced in early-PE (0.83 MoM) but not in late-PE (0.96 MoM). In both early- and late-PE serum PAPP-A (0.55 and 0.84 MoM) was reduced and uterine artery PI (1.61 and 1.25 MoM) was increased. In PE pregnancies there was a significant association between serum PP13 and both uterine artery PI and serum PAPP-A (p < 0.0001 for both). Logistic regression analysis demonstrated that serum PP13 did not improve significantly the prediction of early-PE provided by a combination of maternal factors, uterine artery PI and PAPP-A. CONCLUSION PP13 is implicated in the pathogenesis of impaired placentation and subsequent development of early-PE but measurement of this placental product is unlikely to be useful in screening for the disease at 11-13 weeks.