P 51 Improvement of utero-placental and feto-placental perfusion by Pentaerythrityltetranitrate (PETN) in pregnancies with impaired uterine perfusion in mid-gestion

Introduction In pregnancies complicated by impaired placental perfusion the NO-donor pentaeritrithyltetranitrate (PETN) has been shown to reduce the risk to develop severe intrauterine growth retardation and perinatal death by 39%. The shown effect is most likely based on the vasodilatative effect of PETN. Reduction of resistance in the uterine arteries alone might worthen fetal outcome when accompanied by low perfusion-pressure in the fetal circulation. Here we present the uterine and fetal Doppler parameters assessed during the PETN-trial. Patients and methods 111 pregnancies presenting with abnormal placental perfusion at mid-gestation have been included in the trial. 54 women received PETN while 57 received placebo. Doppler velocimetry measurements of uteroplacental and fetal vessels were monitored biweekly. Results Within the first week of intake, PETN improved uteroplacental perfusion (mean PI 1.26 + 0.36 vs. 1.49 + 0.44; p 0.01). In the PETN group the relative risk for absent or reverse flow in the umbilical artery was 0.565 (0.155-2.066) and 0.580 (0.129-2.606) respectively, for the development of brain sparing 0.488 (0,137-1,737) and for occurrence of a cerebrovascular ratio 1 0.425 (0.194-0.930). Conclusion The profound effect on uteroplacental and fetoplacental perfusion fortifies the positive impact of PETN in pregnancies complicated by impaired placental perfusion.