Scientists from the Children’s Hospital of Philadelphia in Pennsylvania, USA have announced that they’ve been able to keep premature lambs alive in artificial wombs for up to four weeks. This is an exciting development and has led to hopes that the technique could be used to help premature human infants within just a few years.
Alan Flake and his team designed the artificial wombs with human infants in mind. A human pregnancy lasts between 37 and 42 weeks, but the earlier an infant is born the less likely it is to survive. Premature babies who arrive after just 22 weeks have a survival rate of almost zero, but for infants born after 25 weeks the rate has increased to 80%. If artificial wombs could be used to support infants through these critical weeks it could have dramatic effects on their health and development. At the moment premature infants are kept in incubators and helped to breathe with ventilators, but this can cause lasting lung damage and the babies are very vulnerable to infections.
Flake’s team tried to mimic the womb as much as possible, and developed a type of sealed plastic bag filled with water and salts. This closed environment protects a developing foetus (pronounced FEE-tus, this is the term for an unborn mammal that has passed the early stage of its development) from infection and the water/salts mixture mimics the amniotic fluid that protects the foetus inside the womb. Instead of the placenta providing oxygen and nutrients to the foetus, the team designed a device that could be attached to the lambs’ umbilical cords and which used the foetus’ heartbeat to control the oxygen supply.
All of the lambs who were kept in the artificial wombs developed healthily and normally, but a lot more work needs to be done before the system can be used to support premature human infants. The substitute amniotic fluid needs to be improved until it resembles the original much more closely, and the artificial womb needs to be tested a lot more before human trials can begin. Flake and his team envision the system developing into a set-up much like the current incubators, but sealed and with a darkened interior; it’s also been suggested that cameras and speakers could be included so that parents can see and speak to their growing foetus.
If human trials are approved these artificial wombs could only be used to support infants born by C-section, but it would be a remarkable development that could save the lives of many premature babies.