Sildenafil Administration in Early Onset Intrauterine Growth Restriction

Abstract

IntrodutionTwo cases of severe early oset intrauterine growth restriction who presented to us within days of each other were treated with sildenafil and the outcome of the pregnancies was followed up. The first case was a 39year old primigravida who was diagnosed with asymmetrical growth restriction at 22 +4 weeks into the pregnancy which was classified as Stage 3fetal growth restriction according to the Fetal Medicine Barcelona Growth Calculator. The second case studied was a much younger 23year old primip who was also disagnosed with Stage 3fetal growth restriction. Both patients were started on 25mg sildenafil three times a day. In the first case there was improvement in velocimetric profile whilst in the second there was minimal improvement.Early onset intrauterine growth restriction carries a poor prognosis for the foetus, especially with early deterioration of Doppler indices. In such instances, sildenafil can be useful since it acts as a vasodilator and increases uteroplacental flow to promote foetal growth. Case 1A 39year old nulliparous lady was being followed up routinely for her pregnancy with no problems in the first trimester. She had her first antenatal visit at 8weeks gestation and was started on folic acid and vitamin D supplements and 400mg cyclogest twice a week due to her age. A 12 + week dating scan showed a CRL of 72mm which was equivalent to 13 +3 weeks gestation and showed that the pregnancy was low risk for trisomies.At 22 +4 weeks gestation she was noted to have asymmetrical IUGR, with a normal head circumference, a 3week lag in the abdominal circumference and a raised uterine artery Doppler pulsatitility index -left uterine artery PI was 2.96 and the right uterine artery PI was 1.47. An anomaly scan done at the same time was normal showing a normal spine, a three vessel cord, normal abdominal organ and brain development and normal cardiac development and rhythm. She was also noted to have two fibroids, one 5cm in diameter and another 2cm in diameter, with the larger being covered by the placenta.At this point of the pregnancy she was admitted to hospital for further investigations: an infectious screen resulted negative, whilst other blood investigations including a complete blood count, a renal profile and a liver profile were all within the normal range. Blood pressure monitoring was normal, excluding pre-eclampsia, and she was discharged home on 25mg sildenafil three times a day.She has readmitted after 7weeks, at 29 +4 with stage 3 foetal growth restriction. Basic blood investigations and blood pressure monitoring were normal again and she was given two doses of dexamethasone to aid foetal lung maturation. A middle cerebral artery Doppler which was done was normal and a Doppler of the uterine arteries which was repeated showed that it was improving -on the left it was 1.86 and on the right it was 0.93. When Doppler was repeated after two days, PI values of the uterine artery Doppler were 1.6 on the left showing further improvement (Table 1). She was planned to deliver by elective C-...