Circulating angiogenic factors and placental abruption.

OBJECTIVE: Abnormalities in circulating angiogenic factors have been reported in diseases of abnormal placentation, such as preeclampsia and intrauterine growth restriction. Our objective was to determine whether circulating angiogenic factors are altered in another placental vascular disease, abruptio placentae.

METHODS: In a nested case-control study of nulliparous pregnancies, we examined levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) in serum collected prospectively from 31 women who later developed placental abruption and from 31 normal control subjects. All serum specimens were collected before the onset of hypertension or abruption and before labor or delivery. Serum angiogenic factors were compared within 3 gestational age windows: early (20 weeks or less), middle (21-32 weeks), and late (33 weeks or more) pregnancy.

RESULTS: During early pregnancy women who developed placental abruption had lower PlGF and higher sFlt-1 concentrations and higher sFlt-1/PlGF ratios than women with normal pregnancies. In mid-pregnancy these differences became greater, reaching statistical significance for PlGF concentration (431 versus 654 pg/mL, P<.01) and the sFlt-1/PlGF ratio (25.3 versus 2.5, P<.01). When the women with placental abruption were subdivided into those who did (n=10) and those who did not (n=21) develop preeclampsia or gestational hypertension, significant alterations in angiogenic factors were noted only in women who later developed hypertension in pregnancy. Among these women, PlGF concentrations were decreased in mid-pregnancy (160 versus 723 pg/mL, P<.001), and the mid-pregnancy sFlt-1/PlGF ratio was increased (70.1 versus 2.3, P=.001).

CONCLUSION: Serum levels of the proangiogenic factor PlGF were decreased, and those of the antiangiogenic ratio sFlt-1/PlGF were increased in nulliparous women who subsequently developed hypertension and placental abruption.