There is no current evidence from randomised controlled trials to guide the use of intra-amniotic instillation of surfactant for women at risk of preterm birth.
Respiratory distress syndrome caused by a deficiency of natural lung detergent (surfactant) occurs mainly in infants born before term (37 weeks' gestation). The usual treatment includes instilling artificial surfactant directly into the newborn infant's airway followed by mechanical ventilation. However, this process can lead to lung injury, which can affect the infant's long-term health. A potential alternative strategy is to inject surfactant into the amniotic fluid around the fetus close to the infant's mouth and nostrils before birth. Preliminary animal and human study suggests that surfactant enters the fetal lungs through fetal breathing efforts. This has the potential to reduce the need to support the infant's breathing after birth, as well as lung damage caused by mechanical ventilation. This review found no randomised controlled trials of intra-amniotic instillation of surfactant for women at risk of preterm birth. In view of the encouraging results from animal studies and preliminary human study, high-quality studies of intra-amniotic instillation of surfactant for women at risk of preterm birth are needed.
Read the full abstract
Early surfactant reduces mortality and pulmonary complications in preterm infants with respiratory distress syndrome. However, current surfactant administration strategies require endotracheal intubation with or without continued mechanical ventilation. Bronchopulmonary dysplasia and chronic lung disease (CLD) are associated with mechanical ventilation and potentially life-long effects. Non-invasive methods of surfactant administration including intra-amniotic surfactant may avoid endotracheal intubation and mechanical ventilation, potentially preventing development of CLD.
Objectives
To determine if intra-amniotic instillation of surfactant for women at risk of preterm birth, compared to placebo or no treatment or post-delivery tracheal surfactant instillation, reduces morbidity or mortality, or both, in preterm infants. If intra-amniotic instillation is effective, in subgroup analysis to determine the effect of 1) gestational age; 2) type of surfactant; 3) dose; 4) timing; 5) indication; and 6) multiple pregnancy.
Search strategy
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2009), MEDLINE (1950-August 2009), handsearched the Proceedings of Pediatric Academic Societies (American Pediatric Society, Society for Pediatric Research and European Society for Pediatric Research) from 1990-2009 in Pediatric Research Journal and Abstracts online and the Proceedings of Perinatal Society of Australia and New Zealand (PSANZ) (1996-2009). We also searched the Science Citation Index (Web of Science) (August 2009) and checked reference lists of identified studies. We contacted Abbott Laboratories, Inc for unpublished studies.
Selection criteria
Published, unpublished and ongoing randomised controlled, cluster-randomised or quasi-randomised trials of intra-amniotic instillation of surfactant for women at risk of preterm birth, compared to placebo or no treatment or post-delivery tracheal surfactant instillation.
Data collection and analysis
Three review authors independently assessed study eligibility and quality.
Main results
We found no trials were found met the inclusion criteria for this review.
Authors' conclusions
We identified no randomised trials that evaluated the effect of intra-amniotic instillation of surfactant for women at risk of preterm birth. Evidence from animal and observational human studies suggest that intra-amniotic surfactant administration is potentially safe, feasible and effective. Well designed trials of intra-amniotic instillation of surfactant for women at risk of preterm birth are needed.
