The primary endpoint was a combination of severe IVH (grade 3 or higher) and neonatal death. Overall, the primary endpoint occurred in 29 of those randomized to cord milking (12%) and 20 randomized to delayed clamping (8%) – a significant difference.
This finding was largely driven by the treatment differences in the 23-27 week group, Dr. Varner said. Severe IVH occurred in 20 (22%) of those randomized to cord milking and five (6%) of those randomized to delayed clamping – a highly statistically significant difference with a P value of 0.0019.
In the 28-31 week group, there were no cases of severe IVH in the cord milking group, and three cases in the delayed clamping group; the difference was not statistically significant.
Overall, deaths were similar between the cord milking and cord clamping groups (17 and 15, respectively). Most of these deaths occurred in the younger group (14 in the cord milking group and 13 in the clamping group). There were five deaths in the older group: three in the cord milking group and two in the clamping group. None of these differences were statistically significant.
After seeing these data in a preplanned interim safety analysis, the Data Safety Monitoring Board stopped the study, saying that the intervention appeared dangerous for the younger babies, and no better than the delayed cutting and clamping for the older group, Dr. Varner said.
Since the trial was halted, investigators have been dissecting the data to identify any other intracranial hemorrhage risks particular to the infants. They found no significant differences in maternal characteristics at baseline, and – other than age and randomization– nothing significantly different between the infant groups. Severe persistent IVH occurred in almost 70% of the infants born at 23 weeks’ gestation but in only 7% in the delayed cord clamping group. The risks declined rapidly with increasing gestational age, although they were at all times greater than the risk of IVH in the cord clamping group.
“Looking at the data by gestational age, it’s clear that the majority of the severe IVH occurrences were in the 23 weekers, and also occurred in the first 7 days of life,” Dr. Varner said.
The cohort will be followed for at least another year, he added, as investigators track neurodevelopmental outcomes.
Investigators are particularly interested in differences in motor and language skills, as well as general cognitive development.
The study was sponsored by theEunice Kennedy Shriver National Institute of Child Health and Development. Neither Dr. Varner nor any of the coauthors had any financial declarations.
SOURCE: Katheria AC et al. The Pregnancy Meeting, late breaking abstract 1.