Polyethylene bags before cord clamping in very preterm infants: a randomised controlled trial.

Objective: Hypothermia on admission to the neonatal intensive care unit (NICU) is associated with an increased risk of death in preterm infants. There are currently no evidence-based recommendations for thermal care before cord clamping (CC). We wished to determine whether placing very preterm infants in a polyethylene bag (PB) before CC, compared with after CC, results in more infants with a temperature in the normal range on NICU admission.

Design: Randomised controlled trial.

Setting: Tertiary maternity hospital.

Patients: Inborn infants<32 weeks' gestational age (GA).

Interventions: Infants were randomly assigned to have a PB placed before or after CC.

Main Outcome: Rectal temperature within the normal range (36.5°C-37.5°C) on NICU admission.

Results: Between July 2020 and September 2022, 198/220 (90%) eligible infants were enrolled in this study; 99 (44 (44%) girls) were randomly assigned to BEFORE and 99 (53 (54%) girls) to AFTER. Median (IQR) GA 29 (27-31) vs 29 (27-31) weeks, mean (SD) birth weight 1206 (429) vs 1138 (419) g, respectively. The proportion of infants who had normal temperature on NICU admission did not differ between the groups (BEFORE 54/99 (55%) vs AFTER 55/98 (56%), p 0.824). The proportion of infants with a temperature outside of the normal range was similar between the groups; hypothermia (BEFORE 34/99 (34%) vs AFTER 33/98 (34%), hyperthermia (BEFORE 10/99 (10%) vs AFTER 10/98 (10%)).

Conclusions: Placing a PB before CC did not increase the proportion of preterm infants with normal temperature on NICU admission. A large proportion of preterm infants had abnormal temperature. Further studies on thermoregulation before CC are needed.

Trial Registration Number: NCT04463511.