Late-Term Gestation Is Associated With Improved Survival in Neonates With Congenital Heart Disease Following Postoperative Extracorporeal Life Support.

Objective: Several population-based studies have shown that gestational age 39-40 weeks at birth is associated with superior outcomes in various pediatric settings. A high proportion of births for neonates with congenital heart disease occur before 39 weeks. We aimed to assess the influence of late-term gestation (39-40 wk) on survival in neonates requiring extracorporeal life support following surgery for congenital heart disease.
Design: Retrospective cohort study.
Setting: The Royal Children's Hospital, Melbourne, Australia.
Patients: Neonates requiring extracorporeal life support after cardiac surgery for congenital heart disease.
Measurements and Main Results: From 2005 to 2014, 110 neonates (10.5% of neonates undergoing cardiac surgery) required extracorporeal life support after cardiac surgery. Indications were failure to separate from cardiopulmonary bypass in 40 (36%), extracorporeal cardiopulmonary resuscitation in 48 (44%), progressive low cardiac output in 15 (14%), and other reasons in seven (6%). Extracorporeal life support duration was 94 hours (interquartile range, 53-135), and 54 (49%) underwent single ventricle repair. Gestation at birth (n [%]) was as follows: less than 37 weeks, 19 (17%); 37-38 weeks, 38 (35%); 39-40 weeks, 50 (45%); 41 weeks or more, 3 (3%). By multivariable analysis (controlling for age, era of extracorporeal life support 2005-2009 vs 2010-2014, single ventricle status and acute renal failure), gestational age of 39-40 weeks was associated with the lowest odds for intensive care mortality: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.41 (0.12-1.33); for 39-40 weeks, 0.27 (0.08-0.84); and for 41 weeks or more, 1.06 (0.07-14.7). Similar association was also seen in a subcohort of study neonates (n = 66) who were commenced on extracorporeal life support after admission to intensive care: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.52 (0.10-2.80) and for 39-40 weeks, 0.15 (0.03-0.81).
Conclusions: In this cohort of neonates requiring extracorporeal life support following cardiac surgery, 39-40 weeks of gestation at birth is associated with the best survival. The additional maturity gained by reaching a gestation of at least 39 weeks is likely to confer a survival advantage in this high-risk cohort.