Importance of Timing First-Trimester Placental Growth Factor and Use of Serial First-Trimester Placental Growth Factor Measurements in Screening for Preeclampsia.

OBJECTIVE: The aims of this study were to test whether the performance of first-trimester placental growth factor (PlGF) in screening for preterm preeclampsia (PE) is gestational age dependent and to assess the value of serial first-trimester PlGF measurements in discriminating women at risk for PE.
METHODS: PlGF was measured in women with singleton pregnancies at their first antenatal visit at 8+0 to 10+6 and additionally at 11+0 to 14+0 weeks of gestation. The difference in absolute values of serial PlGF measurements was expressed as Δ-PlGF. Values were compared between pregnancies with normal outcome and those complicated by PE.
RESULTS: A total of 814 pregnancies were included, 18 (2.19%) developed PE that required delivery before 37 weeks of gestation. PlGF increases significantly from 8 to 14 weeks of gestation (ρ = 0.63; p < 0.0001) in normal pregnancies, but not so in preterm PE (ρ = 0.034; p = 0.893). PlGF discriminates between PE and uneventful pregnancies only after 10 weeks of gestation. Δ-PlGF was significantly lower in PE 5.3 (-1.1 to 9.3) pg/mL compared to uneventful pregnancies 17.3 (9.8-26.0) pg/mL (p = 0.0011).
CONCLUSION: The discriminatory accuracy of PlGF increases from 10 to 14 weeks of gestation, and serial PlGF measurements might be of particular interest in PE screening.