Objective To evaluate perinatal outcome after sildenafil citrate (SC) administration at the onset of pregnancy in a rat preeclampsia model.Design In vivo animal experimental study.Setting Fundació n IVI-Instituto Universitario IVI, Valencia, Spain.SampleControl and pre-eclampsia-induced pregnant Wistar rats exposed to chronic SC administration.Methods We evaluated the use of SC, which was tested as a potential therapeutic tool to maintain vasodilatation in complicated pregnancies. We have demonstrated previously that SC shows a hypotensive selective effect in normal rat pregnancies when compared with nonpregnant animals.Main outcome measures Maternal blood pressure, weight and mortality during pre-and postnatal development, maternal blood cellularity and haemodynamic changes with maternal and fetal Doppler quantitative indices.Results SC restores normal values of blood pressure, cell count and proteinuria for maternal syndrome. In offspring, SC improves weight gain and increases survival rates without fetotoxic effects. According to the haemodynamic results, SC has a significant effect on the resistance index in the uterine artery in pre-eclamptic animals, as it restores normal values to correlate with an increase in fetal perfusion through the ductus venosus.Conclusions These results suggest that SC administration during pregnancy may have a potential benefit for the treatment of hypertension during pregnancy by reversing the maternal effects of pre-eclampsia and by improving uteroplacental and fetal perfusion.