Ectogenesis, that is the gestation outside of a biological womb, sounds like science fiction. But one of the top stories of 2017 was the success of one group in making artificial wombs a reality—at least for lamb fetuses in later stages of their gestation.
The science is in large part motivated by the high, and steadily rising, number of babies born preterm or before 37 weeks of gestation. According to the Centers for Disease Control and Prevention, one in ten babies are born prematurely in the United States. According to the World Health Organization, that same statistic is true globally, and the United States is one of the ten countries with the highest number of preterm births (although not the highest rate). Premature births can be caused by infection, placenta problems, or genetic problems, but often the cause is not known.
Critically or extremely preterm babies, those born before 28 weeks of gestation, have survival rates that are highly dependent on income levels. In the United States, preterm births have been linked to 17% of infant deaths in recent years, while those babies that do survive have a high likelihood of major complications like cerebral palsy, breathing problems, vision problems, and developmental delays.
But what if babies born prematurely, instead of having to fight for life before they are fully equipped to do so, could be put into an artificial womb-like environment to complete their gestation?
Earlier this year, a group of scientists led by Dr. Alan Flake at the Children’s Hospital of Philadelphia were able to support the gestation of fetal lambs that were around 100 to 120 days in their gestation for up to four weeks in an artificial womb. Since lamb pregnancies are shorter than human pregnancies, these fetal lambs were developmentally equivalent to a human fetus at around 22 to 24 weeks of gestation.
What is an Artificial Womb?
The fetal lambs were placed in what the scientists call a “biobag” of regularly replenished synthetic amniotic fluid. They were connected through their umbilical cords to a life support machine outside of the bag that acted like the mother’s placenta by providing the fetus with nutrition and oxygen while also removing carbon dioxide. The artificial wombs were placed in a dark, warm room where sounds of a mother’s heart beat played.
The artificial womb environment can improve on the more standard incubator because less stress is put on the fetal heart and lungs than when pumps are used to circulate the blood and ventilators are used to force air into the lungs. The sealed environment of the artificial womb can also help keep out infections.
After leaving the artificial wombs, the lambs were observed to have normal growth, lung maturation, and brain maturation. At least one lamb was already one year old at the time the study was published.
Why Are Artificial Wombs Controversial?
The benefits of providing babies born prematurely the opportunity to continue their gestation in a safe and healthy environment that as closely resembles a biological womb are clear. However, extending the artificial womb beyond this purpose raises important questions about how we will have to update our laws and medical ethics standards to keep up with the technology.
For example, if gestation can be done entirely or even mostly outside of a biological womb, this technology could open up options to anyone looking for reproductive assistance, including infertile couples, older people, or transgender people. Artificial wombs could provide environments free of medication or drugs and fine-tuned to specific temperatures, sounds, movement, and balanced diets. Pregnancy is also inherently risky and a more equitable division of parenting roles that could be inspired by gestation outside of a uterus sounds intriguing.
But who is to say what womb environments are “ideal”? Anyone who has been pregnant knows very well that there are far more unknowns than there are certainties as far as the impacts of different factors—anything from prescription medications to types of exercise—on a fetus, most likely due to the complicated ethics of performing any tests on pregnant people. There are bound to be possible microbial benefits, for example, not reproduced in the artificial womb.
Even more complicated questions raised by artificial wombs include who would control the technology?
Even more complicated questions raised by artificial wombs include who would control the technology? Who decides how they are used and for whom? And what does extending gestation outside of the body mean for abortion laws that are linked to fetal viability?
Although it does not hurt to start asking these questions, the reality of complete ectogenesis still remains very far off, if not impossible. Fetal lambs are known to be somewhat similar in their development stages to human fetuses, but the so-called biobags used in the lamb study would require significant adaptations to be suitable for human fetuses. The earliest stages of fetal development are also extremely complicated and still not entirely understood, so extending this technology to even earlier stages of gestation is even more an idea for the distant future.
Dr. Flake noted as much in a press conference announcing their results. He said, “The reality is that at the present time there’s no technology on the horizon. There’s nothing but the mother that’s able to support that period of time.”
Another exciting advancement in the science of birth this year was the birth of the first baby in the United States from a transplanted uterus. (Eight such babies have been born in Sweden since 2014.) Such transplants are usually intended as a temporary addition, as a way of facilitating childbirth before being removed. Such advancements provide important options for would-be parents when more traditional methods fail. We just have to continue to talk about their societal impacts so that our response to such advancements keeps pace with the science.
Until next time, this is Sabrina Stierwalt with Everyday Einstein’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Everyday Einstein on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com.
Image of womb © shutterstock.
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