Perfusion with magnesium sulfate increases sFlt-1 secretion only in the fetal side of placenta of women with preeclampsia

Objective: To examine the effect of magnesium sulfate (MgSO4) on sFlt (soluble fms-like tyrosine kinase)-1 in the fetal and maternal compartments of normotensive and preeclamptic placentas. Methods: Cotyledons of term normotensive and preeclamptic placentas were dually perfused for six hours, with control medium and MgSO4 (6-7 mg %) in the maternal reservoir. Perfusate sFlt-1 concentrations were measured. Results: Median sFlt-1 concentration was higher in the maternal than in the fetal side in both groups and perfusion media (p < 0.0001). When perfused with control medium, the maternal side median sFlt-1 concentration was higher in the preeclampsia than in the control group (p < 0.0001). After pefusion with MgSO4, the median maternal and fetal sides perfusate sFlt-1 concentration were higher in the preeclampsia than in the control group (p < 0.0001). In comparison to perfusion with control medium, the median sFlt-1 concentration of normal pregnant women decreased in the fetal and increased in the maternal side. In the preeclampsia group, only median fetal side sFlt-1 concentration increased. Conclusion: In contrast to normal pregnant women, perfusion with MgSO4 of preeclamptic placentas did not increase their sFlt-1 concentration. This may indicate that MgSO4 role may be limited to its anti-eclamptic and does not affect the anti-angiogenic state associated with preeclampsia.