Deferred Cord Clamping and Weight Difference for Very Preterm Infants

The objective of this study is to estimate the difference in first-recorded weight associated with deferred cord clamping (DCC) among very preterm infants (< 32 weeks' gestational age) using real-world neonatal intensive care unit data.

Retrospective cohort study using the California Perinatal Care Collaborative data from 2016 to 2023 across 138 hospitals. Infants with gestational ages between 22 and 31^6/7 weeks were included. Exclusions were cord milking, death in the delivery room, or missing data. DCC exposure was defined as a delay in cord clamping of at least 30 seconds. Analyses used linear regression adjusting for gestational age (in days) as a second-order polynomial and intrauterine growth restriction (IUGR).

Of 39,013 eligible infants, 6,626 were excluded (cord milking, delivery room deaths, and missing DCC information), leaving 32,387 very preterm infants for the analysis. The mean weight for infants who received DCC was 1,338 g (standard deviation [SD]: 404) compared with 1,290 g (SD: 431) for those who did not. After adjusting for gestational age and IUGR, DCC was associated with 24-g higher first-recorded weight (95% confidence interval: 18-29).

In very preterm infants, at least 30 seconds of DCC is associated with a modest increase (24 g) in first-recorded weight. This finding reinforces evidence from small clinical trials showing increased blood volumes and weight gains attributed to DCC.

· DCC of at least 30 seconds is linked to 24 g higher weights in very preterm infants.. · Weight gain from DCC is modest but aligns with prior physiological evidence.. · Real-world evidence on DCC's impact on early weight is limited..