Artificial uterus: How close is the reality?


The uterus is just another organ that biomedicine will eventually replace, right? Possibly. Medicine does seem to be going in that direction. In recent years, the media have presented stories, including from this writer, that the era of motherless birth beckons, so we should begin pondering the social-political-economic consequences, as we do with all emerging biotechnologies.

Not so fast — some critics say the debate is getting ahead of itself, that there is no need to even discuss artificial wombs yet for several reasons. The main one is that nobody is currently working to develop one, in part because we don’t understand enough about the placenta.

The first point is true; nobody is working on ectogenesis — the term coined by J.B.S. Haldane in 1924, referring to human development outside the mother, through the entire 40-week process, from conception to birth. However, medical science is moving incrementally toward 40-week ectogenesis by gradually pushing back the age that a fetus can be extracted from a womb and survive.

As for the second point, there have been major advances in the realm of artificial placentas; in fact, that developing technology is why new records for fetal prematurity may be just around the corner. Moreover, a true artificial uterus would not need an artificial placenta. The placenta is part of the conceptus package that develops from a fertilized egg. The interface between machine and biology would be in the tissues on the maternal side of the placenta, not the fetal side, and there’s a driver for advances in this area short of the goal of motherless birth: The need for alternatives to advanced lung support for keeping extremely premature infants alive.

Survival of preterm infants with current technology

The closest phenomenon to motherless human birth is preterm birth slightly later than halfway through pregnancy. Capability for rescuing pre-term infants has been increasing dramatically since the 1970s. This has resulted in an increasing number of premature infants surviving when born at gestational ages down to 23 weeks. At that level of prematurity, survival is still only around 20 percent, but it’s increasing in parallel with technology advances. When it comes to the theoretical minimum survivable gestational age, however, not much has changed for almost 30 years. The record is 21 weeks and five days, set back in 1987, and since then no survival has been reported for anyone born younger than 22 weeks gestation. The situation can be compared with old age, where today, due to improving medical knowledge, an increasing number of people live into their hundreds, but the longest verified life-span of any human is 122 years, 164 days.

Just as the ability for humans to live beyond their early 120s will depend on the advent of new approaches such as gene therapy and stem cell-based treatments, fetuses will begin surviving extraction from the womb at gestational ages below 22 weeks, only when neonatologists implement strategies completely different from those used today. But very different strategies are around the corner.

The reason why fetuses can’t be kept alive outside the mother at gestational ages below 22 weeks has a lot to do with the lungs. Before premature birth, mothers can be given corticosteroid treatment to advance fetal lung maturation. Immature lungs do not produce functional surfactant, a substance that lowers the tension in lungs, but surfactant can be administered into the premature newborn’s lungs so they can stretch better, and the newborn can be mechanically ventilated. These treatments work pretty well for low birth-weight infants born at gestational age of 30 weeks or so, but employing them in infants born at 28, 26, or 24 weeks or lower gets progressively trickier. At 21 weeks gestation, the lungs simply are too premature to work with, so if a fetus is to remain alive, it must receive oxygen, and dispose of carbon dioxide, through a pathway that bypasses the lungs.



Of course, there is a pathway for exchanging oxygen and carbon dioxide that bypasses the fetal lungs. It’s the umbilical cord and it connects the fetal circulation to the placenta, which connects with the maternal circulation, while the fetus floats in amniotic fluid inside the uterus. Prior to birth, oxygenated blood from the mother moves through the placenta and umbilical cord and enters the right side of the fetal heart, but most of it does not go to the lungs. That’s because pressure in the fetal lungs is high, plus there are two connections between the right and left circulation, one inside the heart (called the foramen ovale), the other between the pulmonary artery and aorta (called the ductus arteriosus), This anatomy is very different from the arrangement after birth and it allows the oxygen-rich blood from the mother to move directly to fetal body tissues.

Because the lung-supportive treatments used in premature infants today are a delicate balancing act to the point that they become useless below 22 weeks (or in that one case 21 weeks, 5 days), there have been proposals over the last half century to create life-support systems for premature infants that bypass the lungs, similar to how they are bypassed in utero. Now, 50 years ago, the idea was complete science fiction, but the intervening decades saw development of technology called extracorporeal membrane oxygenation (ECMO), which has seen increasing use as a kind of supplemental lung device for people with problems in their pulmonary circulation. Development of ECMO went along with advancing technology used in heart-lung machines, which replaces lungs completely for people going through heart or lung surgery in which the circulation needs to be stopped during the operation. The key technological development has to do with the exchange of gases and precise pumping between blood and air through synthetic membrane-like surfaces. The technology is now so complex that there are ECMO devices that are being called artificial placenta models. These are being studied as an alternative to mechanical ventilation and other lung-based treatments that today are standard for premature infants.

Using an artificial placenta type of device to oxygenate a premature infant’s blood would entail a need to preserve the fetal arrangement of circulation. That means keeping the foramen ovale and ductus arteriosus patent, but that can be done by giving certain treatments and by keeping pressure in the lungs high, which it will be in an infant who is extremely premature and is not given treatments to mature the lungs and make them more elastic.

A complex pathway forward

The process of using an artificial placenta to support a premature infant would involve accessing the umbilical blood vessels and connecting them to the device while inhibiting the process that shifts the anatomy away from fetal circulation. Alternatively, it might make more sense to preserve the fetus’ own placenta, which still would need to integrate with an ECMO system, but this way all of the subtle things that the placenta does that we don’t completely understand will be done.

In either case, the fetus would end up outside of the mother and alive, but it would not be breathing. That potential scenario would change the paradigm regarding fetal viability that underlies current legislative and judicial debates connected with abortion, and raise the question of whether a human developing outside the womb but not yet breathing should be called a premature infant, or an ectogenous fetus.

That would be a qualitative milestone possibly more significant than a quantitative milestone related to pushing back viable gestational age another week or two. Furthermore, depending on it’s gestational age, the fetus/infant might drink formula, but, if removal from the mother is pushed back more, the gastrointestinal tract won’t be any more functional than the lungs. In this case, nutrients would have to be put into the blood along with oxygen, and if the kidneys are not yet working well enough, the placenta will have to be connected  to a dialysis machine to clean the blood.

It’s getting rather complex and becomes more so as we add body systems that may not be functional at earlier and earlier gestational ages, but it’s clear that there is a pathway to ectogenesis. The uncertainly surrounds how many decades it will take to get there, but on the way we also could consider another objection that has been cited against motherless birth, namely that there are other important factors that the mother contributes to fetal development outside the physical and biochemical support that an artificial uterus would replace. The basic argument is that an artificial womb would not be a perfect replace a natural mother no matter how much we learn about the biology, but that could be good or bad. Sure, an artificial womb might be inferior to a healthy mother, but what about a mother who smokes, drinks, is folate deficient, or has any other issue that makes the intrauterine environment less projective than it should be? (No this does not include eating GMO foods, but it could also include mothers who regularly subject their bodies to unproven, untested, unregulated herbal remedies promoted as being healthy on the basis of zero evidence.) Surely, in those cases, the fetus would be better off starting life with no physical connection to the blood stream of such a mother.

David Warmflash is an astrobiologist, physician and science writer. Follow @CosmicEvolution to read what he is saying on Twitter.

  • Rita

    The artificial womb must be created to rescue the FROZEN PEOPLE! As a scripturalist, I say what the Bible says- defend victims, the weak and helpless! The frozen ’embryos’ are frozen people whose parents would be seen as monsters if people saw them fully developed in a freezer!! Yes! It is crucial to save these people stuck in an ‘ice cave’!

    • This could be a nice compromise on abortion, if the to-be-aborted child could be born and live.

  • Erez Shmerling

    An artificial womb is an absolute necessity.
    There is a considerable number of men, who are interested in having kids,but not in women.
    Thus, an artificial womb is warranted.

    • michele lance

      There are men and women in only one human species. We don’t get another species. Although, it is true the 3% of the population that owns 60% of the world’s wealth, are adamant about creating a race of subhumans and will stop at nothing to attempt to accomplish this, and corporate-issue-humans dovetails all too well with this “ideology,”where on Earth is the class of people that are entirely disinterested in exactly half the world’s people? For a man to claim he has no interest in women is quite a sweeping prejudice. If he has no romantic interest in a woman, fine. He can adopt. But to permit the 3% pathological among us to enslave the human race because he wants to raise a kid is irresponsible, uncaring and a pervasive dismissal of the reality a mother is, whether or not yours was healthy, nurturing and loving. That is a man not made well enough in head or heart to enter the transformation into parenthood, which at its wisest, is nothing short of a transformation into selflessness. Are men without mothers ready for this level of human bonding?

      • Russell

        The’ll have fathers – or a single parent families no good?

      • Wellington La

        Ah do not be ridiculous !stop the conspiracies.
        Equal rights for all genders and sexes.

        Ectogenesis will be the best for women.
        You will have no health issues, no chance for implications, no chance of death during labor or deformity due to pregnancy or even C-section.
        Also, no trouble during 9 months ofpregnancy.

        Men will no longer have to assert their dominance in order to “win” women and therefore there will be no fighting, no competing, no violence, no self destructive behaviours. Also, we wont have to take care a wife as all these money could be invested in raising the child better.

        But seriously Michele, what’s wrong with you? men and women are exactly the same and equal. except one has penis and one has vagina. nothing wrong with that. we are both intelligent beings.and equal.
        We should all have equal pay, equal rights, equal freedom and responsibilities and equal privileges?

        • Simon Perseus

          So if you believe all of that then you also must believe that there will be no need for us to have sexual organs. If asked by your government would you have yours and your kids penis removed or allow for your daughter to never give birth and never have the choice of being alive in the natural world, like us? (hypothetically speaking)

          • Wellington La

            You are confusing things.
            I am talking about Choice.
            Choosing to mate with a man/woman OR buy an egg/sperm from bank and use ectogenesis.

            You are talking about a world where the first option (natural mating) would not exist, therefore there would be no Choice.

  • michele lance

    Did this author seriously write, “herbal remedies promoted as being healthy on the basis of zero evidence” ??? “Zero”? Does the writer actually deny the bodies’ need for nutrient and plants’ nutritional content? If this statement (as well, as “ideology”) could even be entertained has having any connection to reality whatsoever, not only would the human race have long ago become extinct, but would the Rockefeller Foundation still be awarding scientists for finding justifications for “containing” medicinal plants from all other human beings outside of pharmaceutical interests?

    • He’s saying that some herbal supplements are detrimental to the health of a fetus, not that all your woo beliefs are invalid.

  • hatetoregister

    Scientists have been working on artificial wombs for years and one was just used to grow a lamb. This article was written in 2016, but it was wrong about where scientists were in the process. Artificial wombs have arrived. They are a definitive game changer. It will only be a matter of time before we have factories where humans are created in a petri dish and grown in artificial wombs.

    The implications are ENORMOUS here!
    First, this would allow women who want kids, but can’t carry them successfully, to be able to have kids using the artificial womb as a surrogate.
    Second, this will allow people to see UP CLOSE the EXACT development cycle of a human AND study the fetus while it is growing.
    Third, this would allow doctor’s to diagnose fetal disorders FAR more quickly AND treat some disorders in the artificial womb.
    Fourth, you could create a whole group of genetically modified humans and women to carry the babies to term.
    Fifth, we could completely eliminate the need for surrogates.
    Sixth, for women having trouble with their pregnancies, the baby can be removed and “replanted” in an artificial womb. This will be especially useful if, for example, a mother develops cancer.
    Seventh, this could be a real game changer for abortion. If you didn’t want to abort, you could give the fertilized egg up, have it removed and “replanted” in an artificial womb and a family who couldn’t have kids with their own egg/sperm combo could have the fetus and be there from “birth”, while the woman/man who wanted to abort go on with their lives.

    There are just so many implications and ways this technology could be used – for good and bad.