Maternal serum placental growth factor isoforms 1 and 2 at 11-13, 20-24 and 30-34 weeks' gestation in late-onset pre-eclampsia and small for gestational age neonates.
To compare the maternal serum concentrations of placental growth factor (PlGF)-1 and PlGF-2 in the first, second and third trimesters in normal pregnancies and in those complicated by pre-eclampsia (PE) or the delivery of small for gestational age (SGA) neonates after 37 weeks. Serum PlGF-1 and PlGF-2 were measured at 11-13, 20-24 and 30-34 weeks' gestation in 50 cases of PE, 99 cases of SGA and 298 controls. The values of PlGF-1 and PlGF-2 at 11-13 weeks were expressed as multiples of the median (MoM) after adjustment for maternal characteristics. The distributions of PlGF-1 and PlGF-2 in cases and controls at 20-24 and 30-34 weeks were converted to MoM of the values at 11-13 weeks and compared. Serum PlGF-1 and PlGF-2 levels were highly correlated and both increased with gestational age. At 30-34 weeks, the median MoM values for PlGF-1 and PlGF-2 in the late PE (4.2 and 4.3) and late SGA (7.2 and 6.0) groups were significantly lower than in the controls (12.8 and 9.9). Combining the two isoforms did not improve the prediction of late PE and late SGA provided by PlGF-1 alone. The performances of serum PlGF-1 and PlGF-2 in the prediction of late PE and late SGA are similar.