Maternal serum placental growth factor at 11-13 weeks in chromosomally abnormal pregnancies.

OBJECTIVES To investigate the potential value of maternal serum placental growth factor (PlGF) in first-trimester screening for trisomy 21 and other major chromosomal abnormalities. METHODS The maternal serum concentration of PlGF at 11 + 0 to 13 + 6 weeks was measured in 609 euploid and 175 chromosomally abnormal pregnancies, including 90 with trisomy 21, 28 with trisomy 18, 19 with trisomy 13, 28 with Turner syndrome and 10 with triploidy. The levels of PlGF were compared in cases and controls, and were assessed for association with free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). RESULTS Logistic regression analysis demonstrated in the euploid group that significant independent contributions for log PlGF were provided by fetal crown-rump length, maternal weight, cigarette smoking and ethnic origin; after correction for these variables the median multiple of the median (MoM) PlGF was 0.991. Significantly lower values were observed in pregnancies with trisomy 21 (0.707 MoM), trisomy 18 (0.483 MoM), trisomy 13 (0.404 MoM), triploidy (0.531 MoM) and Turner syndrome (0.534 MoM). Significant contributions in the prediction of trisomy 21 were provided by maternal age, serum PlGF, PAPP-A and free beta-hCG, and the detection rates of screening with the combination of these variables were 70% and 80% at respective false-positive rates of 3% and 5%. CONCLUSIONS Maternal serum PlGF concentration at 11-13 weeks of gestation is potentially useful in first-trimester screening for trisomy 21 and other major chromosomal abnormalities.