Background: Oligohydramnios has traditionally been associated with adverse materno-fetal outcome. Oligohydramnios without having any underlying pathology had been termed as idiopathic oligohydramnios. Management of idiopathic oligohydramnios had remained always a grey area for obstetrician. Before the advent of ultrasound clinicians had to rely on abdominal palpation and fundal measurements to detect abnormal fluid volume. The condition is usually severe when oligohydramnios or polyhydramnios is detected by clinical examination. With the development of ultrasound imaging the amniotic fluid volume assessment has progressed from a stage of subjective impression to the present state in which relatively sophisticated judgements of fetal conditions can be based on reproducible measurements.
Methodology: This study consists of an analysis of pregnancy outcome in 50 cases with diagnosis of oligohydramnios (AFI less than 5) by ultrasound after 37 completed weeks of gestation compared with 50 controls with no oligohydramnios (AFI more than 8) and matched for other variables like age, parity, gestational age and any pregnancy complication.
Results: Idiopathic oligohydramnios is associated with increased risk of LSCS (22%), Meconium stained liquor (18%), neonatal NICU admisisson (4%) and abnormal ctg (6%).
Conclusion: An amniotic fluid index of < 5 cm detected after 37 completed weeks of gestation in a low risk pregnancy is an indicator of poor pregnancy outcome. Determination of AFI can be used as an adjunct to other fetal surveillance methods. Determination of AFI is a valuable screening test for predicting fetal distress in labor requiring cesarean section.