Delayed vs immediate cord clamping shows no difference in preterm infants
Delayed umbilical cord clamping does not reduce the incidence of death or major morbidities in preterm infants compared with immediate clamping, according to a recent study.
This study involved 1,566 preterm infants (mean gestational age 28 weeks, 56.4 percent male) who were randomized to delayed clamping (n=784; ≥60 seconds after delivery) or immediate clamping of the cord (n=782; ≤10 seconds after delivery). Of these, 65.7 percent were delivered by Caesarean section. The primary outcome was a composite of death or major morbidities such as severe brain injury on postnatal ultrasonography, severe retinopathy of prematurity, necrotizing enterocolitis, or late-onset sepsis in infants at 36 weeks of gestational age. [N Engl J Med 2017;doi:10.1056/NEJMoa1711281]
The combined results of death or major morbidities in infants were comparable between delayed and immediate cord clamping groups (37 percent vs 37.2 percent, relative risk [RR], 1.00, 95 percent confidence interval [CI], 0.88–1.13; p=0.96).
In a post hoc sensitivity analysis, infants who underwent delayed vs immediate cord clamping also showed no significant difference on the incidence of death or other major morbidities, including chronic lung disease (68.8 percent [n=520] vs 66.6 percent [n=498], RR, 1.03, 95 percent CI, 0.96–1.10; p=0.45).
After adjusting for sex, gestational age, and type of delivery, the effect of delayed or immediate cord clamping also showed no significant difference on the occurrence of death or major morbidities in infant at 36 weeks of gestational age.
Overall mortality rate was noted in both delayed and immediate cord clamping groups (6.4 percent vs 9.0 percent, RR, 0.69, 95 percent CI, 0.49–0.97; p=0.03 [unadjusted]).
The results contrasted with that of a previous study which showed that delayed cord clamping provided better neonatal outcomes compared with early cord clamping, particularly with regards to reduced overall mortality, decreased risk of intraventricular haemorrhage, and lower requirement for blood transfusion. [Obstet Gynecol 2014;124:47-56]
To better evaluate the effects of delayed vs immediate cord clamping on overall mortality, the researchers suggested that a larger, more comprehensive trial would be warranted as the study was not powered for mortality and only included short-term results.“[F]ollow-up in childhood is planned … [Furthermore,] the high rate of nonadherence to delayed clamping reflects widespread concern about the possible hazards of delayed resuscitation in preterm infants,” the researchers noted.