In the hopes of someday helping babies born prematurely, a team of scientists from the Children's Hospital of Philadelphia created a device that simulates the conditions inside the uterus.
This artificial womb was originally designed to sustain lamb fetuses — which previous research indicated are good models for human fetal development — by recreating the uterus of a pregnant animal.
The invention has shown significant progress when tested on eight tiny lambs with ages biologically equivalent to premature babies in the 23- to 24-week gestation stage.
Encouraged by their success, the researchers are confident their device could one day be adapted to replicate the uterus of a pregnant woman, possibly in the next three to five years.
What The Artificial Womb Is Intended For
As the researchers explain, the need for such an invention stemmed from the high number of premature babies born every year in the United States.
Almost 30,000 babies a year are delivered in American hospitals at age 26 weeks or younger, more than 10 weeks ahead of the normal gestation period.
This condition, known as extreme prematurity, "is the leading cause of neonatal mortality and morbidity," the researchers document in their paper, published April 25 in the journal Nature Communications.
Extremely premature infants typically weigh about a pound and only have a 30 to 50 percent chance of survival. Nearly 90 percent of those who survive face severe health problems, such as chronic lung disease and complications arising from poor organ development.
Extreme prematurity causes a third of all infant deaths and half of all cerebral palsy diagnoses attributed to preterm births.
"If you can just use this device as a bridge for the fetus then you can have a dramatic impact on the outcomes of extremely premature infants," explained Alan Flake, study lead author.
This would be a tremendous achievement, he added, considering that — as the authors wrote in their paper's abstract — "fetal lambs that are developmentally equivalent to the extreme premature human infant can be physiologically supported in this extra-uterine device for up to four weeks."
How Could This Device Help Premature Babies?
The artificial womb is essentially a clear plastic bag that contains a special liquid fabricated to mimic the amniotic fluid that normally surrounds the fetus in utero.
The system is connected to a circuit that supports oxygen flow via the umbilical cord, allowing the heart to pump blood into a machine outside the artificial womb created to substitute the placenta.
Probably the biggest innovation of this device is that it doesn't rely on a ventilator to help the fetus breathe. Since even gentle pumps produce pressure that can fatally overload an underdeveloped heart, the fetuses are instead suspended in the amniotic liquid.
Blood pumped through the umbilical cord feeds the fetus's bloodstream with oxygen and nutrients, doubling as a system for carbon dioxide removal.
"We tried to develop a system that as closely as possible reproduced the environment of the womb, replacing the function of the placenta," mentioned Flake.
"This, in theory, should allow support of premature infants for a period of weeks, and thereby reduce dramatically their mortality and morbidity rates and improve their outcomes in both the short and long terms," the researcher detailed.
What Are The Potential Ethical Concerns?
The Philadelphia scientific community welcomed the advance in neonatal care this invention is intended to bring, and recognized the artificial womb could help researchers learn more about normal fetal development.
The device was dubbed a "technological miracle" by pediatrician Jay Greenspan, from the Thomas Jefferson University, and "major breakthrough" by Thomas Shaffer, physiology and pediatrics professor at Temple University.
However, other scientists worry about the ethical issues the new invention could potentially raise.
One example is bioethicist Dena Davis, from the Lehigh University in Bethlehem, Pennsylvania. Davis is concerned that, although the device showed success with lamb fetuses, it may not necessarily be a good solution for human fetuses.
She points out that, if the system makes it to human investigations, it could put premature babies at risk for stress and pain, without offering substantial chances of success at the start of the testing trials.
"If it's a difference between a baby dying rather peacefully and a baby dying under conditions of great stress and discomfort then, no, I don't think it's better," says Davis.
If the artificial womb proves successful in helping human preemies, it could end up blurring the lines between a fetus and a baby, potentially impacting abortion politics, she added.
Another bioethicist, Scott Gelfand from the Oklahoma State University, suggests the new technology could be wrongly used to serve coercive purposes.
To support his theory, he hypothesizes that women who want to get abortions could be required to put their fetuses into artificial wombs. At the same time, the device could be used as a loophole by employers looking to avoid maternity leave, or by insurance companies wanting to evade the financial hassles of complicated pregnancies and deliveries.
Moreover, according to sociologist Barbara Katz Rothman, from the City University of New York, the technological transformation of pregnancy could lead to a denied "human connection" among babies being "raised in a machine."
What The Inventors Say
In answer to all these concerns, Flake points out the ethical concerns should be balanced against the risk of death and severe disabilities faced by extremely premature infants.
The scientist clarified the new invention is not meant to extend viability outside of the womb further back than 23 weeks, but to support the infant from 23 weeks to 28 weeks of gestational age, when the effects of prematurity become minimal.
"It's certainly not our goal to extend the limits of viability," says Flake, adding that his team's goal "is to improve survival for extremely premature infants."