# Effect of delayed cord clamping and cord milking on cerebral oxygenation and cardiovascular function: a secondary analysis of the PCI trial

## TL;DR

This study compares delayed cord clamping and cord milking in preterm infants, finding small differences in brain oxygenation and heart function in the first 24 hours.

## Contribution

The study shows delayed cord clamping leads to transiently higher brain oxygenation and lower left ventricular output compared to cord milking in preterm infants.

## Key findings

- Delayed cord clamping increased cerebral oxygenation at 3 and 12 hours compared to cord milking.
- Left ventricular output was lower in the delayed cord clamping group.
- More infants in the delayed cord clamping group required dopamine.

## Abstract

Umbilical cord clamping management may affect cerebral oxygenation (rSO2C), but previous studies have only investigated effects in the first minutes of life. Our objective was to determine whether delayed cord clamping (DCC) and umbilical cord milking (UCM) differently affect cerebral oxygenation and cardiovascular function in the first 24 h of life in preterm infants. A post-hoc secondary outcome analysis of a multicentre prospective randomised clinical trial (PCI), conducted between April 2016 and February 2023 at 8 Italian neonatal intensive care units. The present ancillary study included preterm infants with 23+0–29+6 30 weeks’ gestation. One hundred and five infants received DCC and 104 UCM during resuscitation. Cerebral regional tissue oxygenation (rSO2C) was measured by near-infrared spectroscopy (NIRS) at 3 (T3h), 6 (T6h), 12 (T12h), 18 (T18h), and 24 (T24h) hours of life. Cardiovascular function was assessed by echocardiography within the first 24 h of life. We found that rSO2C was higher at T3h [79 (76–84) vs. 78% (74–82), P = 0.04)] and T12h [79 (76–83) vs. 78% (74–80), P = 0.01] in the DCC than in the UCM group. Left ventricular output (LVO) was lower [196 (182–301) vs. 232 (182–301) ml/Kg/min, P = 0.02] in the DCC than in the UCM group, while right ventricular output (RVO) and superior vena cava (SVC) flow were similar. The need for dopamine was higher (26 vs. 23%, P = 0.02) in the in the DCC than in the UCM group.

Conclusion: rSO2C was transiently higher in preterm infants resuscitated with DCC in comparison with UCM, but this difference was not clinically relevant. The lower LVO value in the DCC group compared to the UCM group deserves further studies to be confirmed and interpreted.

What is Known:

• Umbilical cord clamping management may affect cerebral oxygenation (rSO2C).

• Previous studies showed no differences of brain oxygenation in the first minutes of life due to different timing of cord clamping or umbilical cord milking (UCM).

What is New:

• We showed that rSO2C was transiently higher in preterm infants resuscitated with delayed cord clamping (DCC) in comparison with UCM during the first day of life.

• We found a lower left ventricular output in the DCC group compared to the UCM group, which deserves confirmation and interpretation.

The online version contains supplementary material available at 10.1007/s00431-026-06783-z.