SYDNEY – A shift in practice away from elective late preterm delivery to early term deliveries has shown little effect on neonatal outcomes such as intensive care length of stay, neonatal morbidity, or mortality in a population with major congenital heart disease, a study has found.
Researchers at Columbia University Medical Center and Morgan Stanley Children’s Hospital, both in New York, sought to evaluate the effect of a change in delivery practice that was introduced following the 2009 publication of a study showing improved outcomes in infants delivered after 39 weeks.
Dr Ismee Williams
A review of the medical records of infants with critical congenital heart disease compared outcomes in 878 infants born at a single tertiary center during 2004-2008 to outcomes in 124 infants born in 2010, after the change in practice had been implemented.
There was a significant increase in the mean gestational age (37.8 weeks vs. 38.4 weeks, respectively; P less than .01) and in mean birth weight (2,975 grams vs. 3,134 grams; P less than .01).
However there were no significant differences between 2004-2008 and 2010 data in 5-minute APGAR scores (8.5 vs. 8.6; P = .11), median length of stay (14 days [1-197] vs. 16 days [1-144]; P = .18) and neonatal mortality (6% vs. 11%; P = .07), according to data presented at the International Society of Ultrasound in Obstetrics and Gynecology world congress.
"After the 2009 paper came out, there was a real shift in practice among obstetricians – and also pushed by neonatologists – to try to not deliver patients before 39 weeks," said researcher and fetal cardiologist Dr. Ismee Williams, of New York–Presbyterian Hospital/Columbia University Medical Center.
"Then our goal, instead of being 38 weeks, was 39 weeks, and we would not schedule anybody for induction or a cesarean section unless they were 39 weeks and change," Dr. Williams said in an interview.
As a result of the change in practice, there were significant decreases in scheduled cesarean delivery from 2004-2008 to 2010 and in scheduled induction, but significant increases in urgent inductions, urgent cesarean deliveries, and cesarean deliveries after labor.
"We were happy to see that the change did affect a consequent increase in gestational age and birth weight, but we were somewhat surprised that it didn’t affect length of stay," Dr. Williams said.
Given that the study was conducted in a population with congenital heart disease, she said a likely explanation was that most of the infants would require surgery before they were discharged from hospital.
Dr. Williams said that the study didn’t look at maternal length of stay in hospital or other indicators of maternal morbidity, but she noted perhaps the next step would be to examine more closely the effect of the change in practice on mothers.
"However, it’s possible that, in the congenital heart disease population, whether or not you deliver at 38 or 39 weeks, we’re not seeing that big of a difference in terms of the neonatal outcomes or a big impact on big markers of morbidity like length of stay," Dr. Williams said.
There were no conflicts of interest declared.