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Mixed Results With Umbilical Cord Milking in Struggling Newborns

— No drop in NICU admission rates versus early cord clamping, but there were other boons

Ƶ MedicalToday

ANAHEIM, Calif. – Umbilical cord milking offered some benefits in non-vigorous newborns, but fell short for cutting admission to the neonatal ICU (NICU), according to a large randomized trial.

Infants (born at 35-42 weeks' gestation) who underwent umbilical cord milking were less likely to need delivery room cardiorespiratory support (adjusted odds ratio 0.65, 95% CI 0.52-0.80) and therapeutic hypothermia (OR 0.57, 95% CI 0.33-0.59), and were less likely to suffer moderate-to-severe hypoxic-ischemic encephalopathy (HIE, OR=0.68, 0.41-1.13), reported Anup C. Katheria, MD, of Sharp Mary Birch Hospital for Women and Newborns in San Diego, and colleagues.

They also had higher hemoglobin levels (last squares mean difference 0.7 g/dL, 95% CI 0.3-1.1), he said in a presentation at the American Academy of Pediatrics annual meeting. The findings were published in August 2022 in the .

However, the difference in the primary endpoint between umbilical cord milking and early cord clamping was not statistically significant with 23% in the former versus 28% in the latter landing in the NICU (modeled OR 0.69, 95% CI 0.41-1.14), according to the authors.

Still, Katheria told Ƶ that taken as a whole, "the data [are] pretty convincing that umbilical milking should be considered as standard practice for these babies. It is definitely better than clamping the cord early."

Heike Rabe, MD, of Brighton and Sussex Medical School in England, seconded that idea. Rabe, who has extensively, explained to Ƶ that is recommended to boost blood flow in non-vigorous infants by groups such as the . However, that approach goes against what clinicians are accustomed to doing which is early cord clamping.

When newborns are struggling at birth, "it is difficult to change the behavior of birth attendants who want to hand over the baby to a pediatrician. This is where cord milking comes in as a back-up strategy if clinicians feel that they cannot wait for at least 1 minute" before clamping the cord, said Rabe, who was not involved in the current study.

Umbilical cord milking "consists of encircling the cord with thumb and forefingers, gently squeezing, and slowly pushing the blood through the cord to the infant's abdomen," according to an NIH press release. Katheria noted that there's long been talk of umbilical cord milking -- ancient Greek philosopher would revive dying newborns by squeezing the umbilical cord before cutting it -- to help non-vigorous babies get one final burst of rich placental blood.

Katheria's group reported that currently no major professional groups recommend umbilical cord milking in healthy or non-vigorous newborns. ACOG in 2020 that "infants requiring resuscitation may benefit considerably from placental transfusion, but their need for immediate attention raises questions about whether they should undergo (early) cord clamping or whether umbilical cord milking may offer unique benefits."

In a 2019 , Katheria and colleagues reported that "umbilical cord milking vs delayed umbilical cord clamping among preterm infants born at less than 32 weeks' gestation, there was no statistically significant difference in the rate of a composite outcome of death or severe intraventricular hemorrhage, but there was a statistically significantly higher rate of severe intraventricular hemorrhage in the umbilical cord milking group."

The current study was done from 2019-2021 at 10 international medical centers with 872 non-vigorous newborns who underwent umbilical cord milking (about 38% of mothers were white with a mean age around 31) and 858 who underwent early cord clamping (about 36% white; mean age around 30). All were born at 35-42 weeks gestation and appeared to be faring poorly within 10-15 seconds of birth with poor tone, pale color, or inability to breath.

Umbilical cord milking was done with pumping 20 cm of cord over 2 seconds and that was repeated three more times. Alternatively, the umbilical cord was clamped within 60 seconds.

Katheria pointed out that "the big safety outcome we were really interested in was brain injury -- HIE, which stands for low oxygen and low blood status." His group found a lower rate of HIE in the umbilical cord milking group versus the early clamping group (3.3% vs 4.7%) and "this was great. A significant reduction was important," he said, adding "these babies did not end up needing as much oxygen or ventilation or CPR; all the things that you have to do in a baby who's limp, blue, and not breathing."

The authors reported that 60.7% of the umbilical cord milking group required cardiorespiratory support versus 70.5% of the early cord clamping group. There was one death in the delivery room in the early clamping group. That live-born infant was not successfully resuscitated, with death at 20 minutes after birth and a postmortem diagnosis of HIE.

Katheria also emphasized that there's no cost to umbilical cord milking and that it takes just a few seconds to complete. "It's not just blood that you're giving these babies," he said. "Placental blood, cord blood, is full of billions of stem cells. They're an important part of their growth and development and may even protect them from injury. So filling [the infants] up with this additional cord blood may have a lot of [beneficial] downstream effects that we're just not even aware of yet."

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    Randy Dotinga is a freelance medical and science journalist based in San Diego.

Disclosures

The study was funded by the National Institute of Child Health and Human Development.

Katheria and co-authors, as well as Rabe, disclosed no relationships with industry.

Primary Source

American Academy of Pediatrics

Katheria AC, et al "Umbilical cord milking in non-vigorous infants: A pragmatic cluster-randomized crossover trial" AAP 2022; Abstract O1035.

Secondary Source

American Journal of Obstetrics & Gynecology

Katheria AC, et al "Umbilical cord milking in nonvigorous infants: a cluster-randomized crossover trial" Am J Obstet Gynecol 2022; DOI: 10.1016/j.ajog.2022.08.015.