Maternal Serum Placental Isoferritin Levels in Pregnant Women with Abnormal Uterine Artery Doppler Velocemitry

ABSTRACT

High levels of placental isoferritin (PLF), which is an immunosuppressive cytokine, have been demonstrated in the sera of pregnant women. In the current study, 41 pregnant patients at high risk for placento-vascular complications, such as preeclamptic toxemia (PET) and/or intrauterine growth retardation (IUGR) were preselected if abnormal uterine artery Doppler measurements appeared at the time of the 20th-22nd gestational week scan. Concomitantly, venous blood was collected from each patient. PLF serum concentrations were determined by specific enzyme-linked immunoadsorbent assay (ELISA). The PLF levels were compared to 44 healthy pregnant women at midgestation with uneventful pregnancy outcomes. The aim of the current study was to evaluate the contribution of PLF measurement in this preselected group. Following delivery, two subgroups of abnormal uterine artery Doppler waveforms were retrospectively defined. Twenty-one (51%) patients had normal outcomes, whereas 20 (49%) had pathological outcomes mainly complicated by PET and/or IUGR. Significant differences in PLF serum levels were observed between the control group (84 ± 64 U/mL; median 84 U/mL) compared with those of the study subgroup with normal outcome (31 ±19 U/mL; median 23 U/mL) and with the pathological outcome subgroup (19 ± 8 U/mL; median 17 U/mL) (p < 0.05). Nineteen percent of the normal subgroup compared with 45% of the pathological subgroup were found to have a serum PLF concentration < 19 U/mL. This cutoff level was achieved based on receiver operating characteristic (ROC) curve. The combination of abnormal uterine artery wave forms followed by low serum PLF < 19 U/mL increased the positive predictive value to 63%, as compared with up to 30% positive predictive value only for the abnormal Doppler waveforms. The current preliminary results concur with previous studies suggesting that low PLF levels may reflect abnormal placentation. The exact contribution of PLF and uterine artery Doppler waveforms in monitoring patients for placento-vascular complications should be the design of a future, larger, prospective study.

Keywords

Doppler velocemitry - intrauterine growth retardation - placental isoferritin - preeclamptic toxemia