Placenta growth factor is not an early marker for the development of severe preeclampsia

OBJECTIVE: Our purpose was to determine whether plasma concentrations of pl acenta growth factor may be used as a marker for women who ultimately have severe preeclampsia. STUDY DESIGN: We performed a nested case-control study to compare plasma co ncentrations of placenta growth factor in women with severe preeclampsia wi th the concentrations in normotensive pregnant control subjects. Plasma sam ples were collected at <20 weeks' gestation and again in the third trimeste r. Twenty-two women who ultimately had severe preeclampsia were matched for gestational age at delivery with 22 normotensive control subjects. Placent a growth factor concentrations were measured by a specific antigen capture enzyme-linked immunosorbent assay. Comparisons were made by using the Mann- Whitney U test for nonparametric data such as placenta growth factor concen trations. The Student t test was used for parametric data. RESULTS: A total of 880 pregnant women were screened. Severe preeclampsia d eveloped in 22, for an incidence of 2.5%. As expected, women with severe pr eeclampsia had significantly higher systolic and diastolic blood pressures, and their infants had lower birth weights. Placental weights at delivery w ere similar between those with severe preeclampsia and control subjects (65 9 vs 699 g; P=.51). During the third trimester, the median placenta growth factor concentrations were significantly lower in women with severe preecla mpsia than in normotensive control subjects (125 vs 449 pg/mL; P=.003). Whe n samples drawn at <20 weeks' gestation were compared, there was no differe nce between the group with severe preeclampsia and those who remained normo tensive (98.8 vs 56.34 pg/mL; P=.15). CONCLUSION: During the third trimester, patients with severe preeclampsia h ave decreased maternal concentrations of placenta growth factor. This diffe rence is not seen earlier in pregnancy. Lower concentrations of placenta gr owth factor may be a result of severe preeclampsia rather than a causal fac tor Placenta growth factor is not a good marker for the subsequent developm ent of severe preeclampsia.