Researchers at the Philadelphia Children’s Hospital in the USA have perfected equipment that reproduces the environment of a uterus. Testing has successfully been carried out on lamb fœtuses, where the development of the lungs in utero is "very close" to that of humans. It is hoped that an "artificial uterus" of this kind could work miracles on premature babies. The researchers point to a reduction in both mortality rates and handicaps linked to organs that are not fully developed.
An "artificial uterus" has been designed which improves the survival rates of very premature babies and reduces the negative effects of a shortened pregnancy. The equipment has been perfected by researchers at the Philadelphia Children’s Hospital in the USA, and has already had encouraging results on lambs. It is hoped that it will have clinical tests in the "next three to five years".
Maintain vital functions
In the results of their study, which was published recently in the journal 'Nature Communications', the experts state that they were able to develop lamb fœtuses for four weeks. These were then placed in the equipment after 15–16 weeks of gestation – a stage at which the development of their lungs is equivalent to that of an "extremely premature" human fœtus of 23–24 weeks.
Seven of them were kept alive for over 25 days. According to the researchers, this is the first time that an external system has been able to maintain vital functions and ensure the development of an animal fœtus for so long.
Plastic sac filled with fluid
The "artificial uterus" is made up of a plastic sac filled with fluid, with a system to provide oxygen which is linked to the umbilical cord, which thus reconstitutes the environment in which the fœtus develops before birth. Transposing this procedure to extremely premature babies, by maintaining them through to the 28th week of gestation, would bring down the mortality rate from 90% to less than 10%, and the risk of negative effects from 90% down to 30%, said Alan Flake, one of the authors of the study.
New-borns are considered premature if they are born before 37 weeks, and "critically premature" before 26 weeks. The limit at which a fœtus is said to be viable is estimated at 22–23 weeks of pregnancy. Despite the progress that has been made in neonatal care, mortality rates at this stage, where the baby weighs less than 600 grams, remain very high (50%–70%).
If the baby then survives, it is "at a very high cost in terms of quality of life, with a 90% risk of negative effects such as chronic pulmonary diseases or complications linked to the lack of development of the organs", which can represent "a life-long handicap", said the press release accompanying the study.
"Conduit between the uterus of the mother and the outside world"
Very premature babies nowadays who cannot breathe autonomously are intubated and put on an artificial respirator, which halts the development of their lungs and exposes then to infections, explains Flake, who is a foetal surgery expert. "These children urgently need a conduit between the uterus of the mother and the outside world."
The researchers need to continue their testing on lambs, whose lungs develop in utero in a "very similar way" to humans, before hoping to move on to human testing. While lambs are suitable for studying the development of the lungs, they are less useful when it comes to estimating the risk of intracranial haemorrhages, which is one of the main complications among very premature babies.
Contact Allianz Partners