Cutting the cord is a momentous event in a baby’s life.
For nine months, the developing fetus is attached to its mother by the umbilical cord. Then, moments after birth, that cord is severed.
Now, research suggests there may be benefits to keeping mom and baby attached a few minutes longer.
Those benefits, researchers say, likely have to do with iron.
Waiting a few minutes before clamping the umbilical cord allows more iron-rich blood from the placenta to reach the newborn.
Iron deficiency occurs in about one in six American babies, and it’s more common among those clamped quickly, said Ola Andersson, a neonatologist and pediatrician at Uppsala University in Sweden, who led a study published today in JAMA Pediatrics. Babies who are anemic often appear tired and pale.
His previous research has shown that babies whose cords were clamped a few minutes later than usual were 90% less likely than others to have iron-deficiency anemia when they were 4 months old.
The benefits of those extra few minutes may last a long time.
In the new study, Andersson found that healthy, full-term newborns whose umbilical cords were left attached for three extra minutes had better fine motor control when they reached preschool than those clamped immediately. Some 4-year-old boys who were clamped later even appeared to have better social skills.
Iron is essential to the developing brain, he said, and deficiencies during early months — perhaps linked to early clamping — could affect nerve and muscle control, making it harder for the child to later control a pen or interact comfortably with peers.
Andersson’s study marks the first time researchers have followed children to see whether the clamping makes a difference later in life. In 2011, he published a study of 400 healthy, full-term babies showing that those clamped later fared better; the new study of 263 of those children extends those findings by nearly four years.
Boys showed more benefit than girls, probably because they are more likely to be iron-deficient, Andersson said.
Immediate clamping started about 70 years ago out of concern that leaving the delivered infant attached to the placenta could rob the mother of too much blood.
But those doctors overestimated the benefit to the mother and didn’t look at the impact their change had on the babies, said Heike Rabe, a researcher at Brighton and Sussex Medical School and University Hospitals, in the United Kingdom, who wrote an editorial accompanying the study.
For babies born at full-term, “we should trust nature more than we do now,” she said.
Rabe has published reviews showing that delaying clamping for 30 seconds, or squeezing the umbilical cord to get the blood out faster, is also better for premature babies.
Many countries and professional organizations, including the American Congress of Obstetricians and Gynecologists, have called on obstetricians to delay cord clamping in premature babies when feasible. There was not enough evidence before to extend that recommendation to full-term babies, but Rabe thinks this study should tip the balance in favor of delay.
Kjersti Aagaard, vice chair of obstetrics and gynecology at Baylor College of Medicine and Texas Children’s Hospital, is more skeptical. She said the decision about when to clamp should be made between the doctor and parents, depending on the delivery, the health of the baby and the mother’s condition.
“The most important thing for parents to be talking with their provider about is how will we adapt to the delivery as it emerges,” she said.
Despite its four-star score, this story has the potential to lead casual readers astray, since it’s not quite as careful as a competitor NPR story in describing the potential benefits and harms of leaving newborns’ umbilical cords attached to Mom longer. Both stories reported on a study of only 263 children in Sweden that showed modest improvements in fine-motor skills for children whose cords were left intact for three minutes instead of cut after ten seconds. But this story didn’t give much context — it launches headlong into the potential reasons why delayed clamping might help, without carefully weighing the harms and considering the quality of the evidence.
Estimates are that one out of six babies born in the US suffers some anemia, or a low level of iron in their blood. Delaying of clamping the umbilical cord between mother and child might be a way to prevent that. It is already recommended for premature infants. However, this small study from Sweden shows only modest results in fine-motor skills for children four years later. The researchers themselves write that “larger studies” are necessary before all birth practices should be changed.
The difference of slowing down the clamping of the newborn’s umbilical cord does not seem to add any cost to care for a delivery. The story might have talked about potential “savings” if widespread use of this new technique made iron-deficiency for babies less common in US. But any benefit would be difficult to quantify.
The story asserts that healthy, full-term newborns whose cords were left unclamped for three extra minutes at birth “had better fine motor control when they reached preschool” than a control group whose cords were clamped immediately. But we aren’t provided adequate context or any numbers for how much better some of the children performed. Was this a large, meaningful benefit? Or something barely distinguishable from statistical noise?
The story also notes: “His previous research has shown that babies whose cords were clamped a few minutes later than usual were 90% less likely than others to have iron-deficiency anemia when they were 4 months old.” This is an incomplete representation of the benefit, since the absolute reduction in anemia was lower than this number suggests.
The story does not talk about potential harms to the newborn, such as jaundice, although it does mention the original rationale for quick cord-clamping, to limit the blood loss to the mother.
The story does not include many details. The study was a randomized controlled trial which followed up a group of children four years after their birth to look for neurological differences. In the study publication itself, the authors wrote: “Future research should involve large groups.” The study was of only 263 children.
Mentioning the dropout rate for the study, which the authors acknowledge was “relatively high” at 31.2%, would have been another way to provide context. In the study, the researchers noted that they “cannot exclude a possible bias in the overall development of the children whose parents chose to return for the follow-up…” This means that it’s possible that parents who returned for the follow-up 4 years later might be raising their kids differently than those who dropped out, and that those differences had some impact on the test scores. In other words, maybe the delayed cord-clamping 4 years ago wasn’t really cause of the better test scores.
We also have concerns about the story’s description of previous research conducted by one of the study authors. The story says:
“In 2011, he published a study of 400 healthy, full-term babies showing that those clamped later fared better; the new study of 263 of those children extends those findings by nearly four years.”
The phrase “extends those findings” is not as accurate as it could be. The study four years later was not measuring the same endpoints, but was investigating some rather subjective measures including surveys that parents filled out about their children’s behavior. The 2011 study was of iron deficiency, not fine-motor tasks. Linking the two studies so closely provides a neat narrative, but without the necessary context, it’s misleading.
There was no disease mongering.
The story quoted a separate source not involved in the study with a different point of view. And while we applaud the story’s inclusion of that voice, we think the air time could have been used more fruitfully. Asking the reader to talk to a doctor/make an individual choice [Dr. Ishani speaking here as someone such people are sent to], without more explanation as to why they would choose one route or another, misses an opportunity to deliver succinct, useful information about the downsides of delayed clamping.
There’s either early or late clamping, and the article describes both methods
Hypothetically, a delay in cord-clamping is something equally available to all those who deliver babies and their patients. But in the real world it’s different: A delay is only available to a woman if her doctor/health system decides to offer it (barring the role of patient advocacy). The story didn’t explore how common delayed cord-clamping is, or how willing doctors are to consider it. But since the story does at least suggest that women can raise the issue with their doctor and make a shared decision about what to do, we’ll give the benefit of the doubt.
The story explains that this idea is not novel, and indeed is already recommended for premature infants.
The story quotes an additional source and did not rely on a news release.