The Epidemiology of Respiratory Failure in Neonates Born at an Estimated Gestational Age of 34 Weeks or More.  Reese CH and The Near-Term Respiratory Failure Research Group.  Journal of Perinatology (April 2005): 251-257.

Objective. To prospectively evaluate the primary causes for the use of mechanical ventilation in near-term neonates and to determine the rates of death, chronic lung disease, and neurological complications in these infants.

Study design.  We collected data on 1011 neonates who were 34 weeks' estimated gestational age; intubated within 72 hours of birth; and expected to require ventilation for more than 6 hours. 

 Results. The study population had a mean estimated gestational age of 372 weeks; had a mean birth weight of 2.90.6 kg; and were predominantly male (62%), white (69%), and delivered by cesarean section (55%). Respiratory distress syndrome (n=437) was the most common pulmonary illness. Chronic lung disease was diagnosed in 109 (11%); neurological complications were reported in 86 (9%); and 51 (5%) patients died.

Conclusions.  Neonates 34 weeks who require mechanical ventilation represent high-risk populations who have significant morbidity and mortality.

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Comments:  This study quantitates what practicing neonatologists experience on a regular basis – that classic hyaline membrane disease among infants ≥ 34 weeks gestation is a common event in the NICU.  In fact, in this population, HMD was a nearly fivefold more common explanation for mechanical ventilation than was meconium aspiration syndrome.  ECMO was utilized in only 3.6% of the infants of which nearly half had congenital diaphragmatic hernia or other lung hypoplasia.  In my mind, this information raises the question of whether a more aggressive obstetrical approach to the management of preterm labor at 34 to 37 weeks gestation is warranted.  In my practice, many of these pregnancies are allowed to deliver without the benefit of antenatal steroids or tocolysis more aggressive than hydration and a dose of subcutaneous terbutaline.  Hopefully, to assess the feasibility of a clinical trial, there will be further data forthcoming from this database that captures for each week of gestation the numbers of infants with HMD as nominators and total deliveries (as denominators). MLH.