Babies born after preterm prelabour rupture of membranes (PPROM) between 16 and 26 weeks of pregnancy are prone to underdevelopment of the lungs. When the membranes containing the fluid that surrounds the baby (amniotic fluid) rupture, a shortage of this fluid can occur, a condition that is called oligohydramnios. Oligohydramnios is thought to interfere with normal lung development so that it is delayed, resulting in a condition that is called pulmonary hypoplasia.

Pulmonary hypoplasia can present as severe breathing problems or as milder and even transient breathing problems. It can be accompanied by bleeding in the lung and can also result in chronic breathing problems due to scarring of lung tissue. There may also be neurological complications, fetal deformities and neonatal sepsis with oligohydramnios.

Replacement of fluid via a needle passed through the abdominal wall in the uterine cavity and into a pocket of amniotic fluid, (transabdominal amnioinfusion) under ultrasound guidance has been proposed to improve pregnancy outcome. Most clinical experience suggests that amnioinfusion is safe for both the mother and the baby, however, we did not identify any randomised trials of transabdominal amnioinfusion following PPROM before 26 weeks for inclusion in this review. Currently, there is no evidence to evaluate the use of transabdominal amnioinfusion in women with oligohydramnios following  rupture of fetal membranes before 26 weeks for improving birth outcomes.