Based on previous studies, Both sildenafil and L-arginine helped to improve idiopathic oligohydramnios.

In this study, Level of improvment of oligohydramnios will be compared. As well as, NICU admission to neonates of pregnancies complicated by idiopathic oligohydramnios. The end goal is to help physicians use the best drug for their patients.

Inclusion Criteria:

• Pregnant women with gestational age between 26-37 weeks
• Pregnant women whose age is < 35 years
• Woman with other indication for elective caesarean section.
• Women carrying a single fetus with no major anomalies.
• Initial amniotic fluid index <8cm determined by reliable pelivabdominal ultrasound.

Exclusion Criteria:

• Women complaining of other obstetric disorder such as, PPROM, preeclampsia, or diabetes.
• Women with chronic illness such as, chronic hypertension, autoimmune disease or kidney disease.
• Women who received other treatments for oligohydramnios in current pregnancy.
• Women who smoke.
• Fetuses with major congenital anomaly.