Objective: The purpose of this study was to evaluate first-trimester serum placental protein 13 (PP13) as a screening test for preeclampsia and intrauterine growth restriction (IUGR).
Study design: We performed a prospective, nested case-control study in the Massachusetts General Hospital Obstetric Maternal Study. PP13 was measured by solid-phase sandwich enzyme-linked immunosorbent assay in serum samples that were collected at the first prenatal visit (9-12 weeks of gestation) from women who subsequently experienced preeclampsia (n = 47), IUGR (n = 42), or preterm delivery (n = 46). Women with uncomplicated term deliveries served as control subjects (n = 290) and were matched to cases by gestational age when serum was collected and for the duration of specimen storage.
Results: The median first-trimester PP13 level was 132.5 pg/mL in the control subjects. Median PP13 levels were significantly lower among women who had preeclampsia (27.2 pg/mL; P < .001), IUGR (86.6 pg/mL; P < .001), and preterm delivery (84.9 pg/mL; P = .007). When PP13 was expressed as multiples of the gestational age-specific medians among the control subjects, the multiples of the medians were 0.2 for preeclampsia, 0.6 for IUGR, and 0.6 for preterm delivery (P < .001 for each disorder compared with control subjects). Receiver operating characteristic analysis yielded areas under the curve of 0.91, 0.65, and 0.60 for preeclampsia, IUGR, and preterm delivery, respectively. At a 90% specificity rate, the corresponding sensitivities were 79%, 33%, and 28%, respectively.
Conclusion: The screening of maternal PP13 levels in the first trimester is a promising diagnostic tool for the prediction of preeclampsia with high sensitivity and specificity.