Pravastatin and L-Arginine Use in Early-Onset Severely Growth-Restricted Dichorionic Twins: A Case Report.

BACKGROUND Fetal growth restriction (FGR), or intrauterine growth restriction, is more common in twin pregnancies. Pravastatin enhances nitric oxide synthesis and placental vasodilation, and L-arginine, a precursor to nitric oxide, reduces pulmonary artery resistance. There is evidence that combined pravastatin and L-arginine can improve blood flow to the placenta, prolong pregnancy, and prevent preeclampsia in complicated pregnancies, including monochorionic twin pregnancies. CASE REPORT A 35-year-old patient, gravida 1, with dichorionic twin gestation conceived via intrauterine insemination presented at 16 weeks of gestation with severe FGR of both fetuses. At 21 weeks and 5 days of gestation, umbilical artery Doppler studies demonstrated absent end-diastolic flow for twin B. No anatomic fetal anomalies were detected. Treatment with pravastatin 40 mg and L-arginine 1.5 g daily was initiated at that point and continued until delivery. The pregnancy was prolonged until 32 weeks and 1 day of gestation, with inpatient monitoring when preeclampsia with severe features developed and delivery was recommended. She underwent a primary classical cesarean delivery. Both fetuses were severely growth-restricted, less than the 1st percentile for gestation. Both twins survived without major morbidity. CONCLUSIONS This report presents the case of a 35-year-old woman with a dichorionic twin pregnancy with FGR diagnosed at 16 weeks of gestation, managed with pravastatin and L-arginine, resulting in twin delivery at 32 weeks. This report supports findings from recent studies that combined pravastatin and L-arginine can improve fetal development and survival in FGR within monochorionic twin pregnancies. Adequately powered and randomized trials are needed to confirm this finding.