Relationship between first-trimester serum placental protein-13 and maternal characteristics, placental Doppler studies and pregnancy outcome.

OBJECTIVE: To examine potential correlations between maternal serum placental protein-13 (PP-13) and first trimester maternal and placental factors, and to evaluate the association of this marker with adverse pregnancy outcome. METHODS: Serum samples from prospectively enrolled patients between 11 and 13 weeks and 6 days were analyzed for PP-13 using an ELISA assay. The relationships between maternal serum PP-13 levels and gestational age, maternal age, ethnicity, parity, smoking status, body mass index (BMI), mean arterial blood pressure, uterine and umbilical artery Doppler parameters were examined. The association between first-trimester PP-13 levels and subsequent pre-eclampsia and delivery of a small for gestational age (SGA) neonate was also investigated, after excluding patients who received aspirin. RESULTS: In 908 patients, PP-13 levels ranged from 8.0 to 537.5 pg/mL. A significant negative correlation was identified between PP13 and BMI (Spearman rho -0.20, P<0.0001). Smoking significantly decreased PP-13 (P<0.01). No relationship was identified with the other parameters. In a subgroup of 668 low-risk patients who did not receive aspirin, PP-13 levels were not associated with development of pre-eclampsia, SGA or the combination of them. CONCLUSION: First-trimester PP-13 levels are significantly correlated with BMI and smoking. These correlations appear independent of uterine and umbilical artery resistance. In low risk patients, PP-13 levels fail to predict the risk for pre-eclampsia or SGA.

Prediction of preeclampsia by placental protein 13 and background risk factors and its prevention by aspirin.

AIM: Evaluation of placental protein 13 (PP13) and risk factors (RFs) as markers for predicting preeclampsia (PE) and use of aspirin for PE prevention. MATERIALS AND METHODS: First-trimester pregnancy screening was based on having PP13 level ≤0.4 multiple of the median (MoM) and/or at least one major risk factor (RF) for PE. Management was by routine care or combined with daily treatment with 75 mg aspirin between 14 and 35 weeks of gestation. RESULTS: Of 820 deliveries, 63 women developed PE (7.7%). Median PP13 levels was 0.2MoM in the PE group compared with 0.83MoM among unaffected and 1.0MoM in unaffected not treated with aspirin (P<0.0001). Low PP13 was a better predictor for PE versus major RFs, particularly for young nuliparous. Combining low PP13 with RFs increased prediction accuracy. Mean arterial pressure (not included in the initial prediction), could add to prediction accuracy when combined with low PP13 and RFs. PE prevention by aspirin was most effective when the risk was determined by low PP13 alone, less effective for combining low PP13 with RFs, and ineffective when determined by RFs alone. CONCLUSION: When PE risk is determined by low first trimester PP13 or by combined low PP13 and RFs, prevention with aspirin is warranted.