The possibility of prolonging a baby’s effective gestation period outside of the womb has long been viewed as the holy grail for treating extremely premature infants, but until now scientists have struggled to realize this immense technical challenge.

Pediatric researchers designed a unique artificial womb in the hopes of someday using the device to transform care for extremely premature babies, by mimicking the prenatal fluid-filled environment. So far the device has only been tested on fetal lambs and the technology could be used on humans in 3-5 years.

Extreme Prematurity

Unfortunately, extreme prematurity is the US nation’s leading cause of infant mortality and morbidity. According to statistical data, one in ten U.S. births is premature, requiring special hospital care. An estimated 15 million babies are born too early every year. Almost 1 million children die each year due to complications of preterm birth.

There is a high likelihood of lifelong disability among those that do survive, who have a 90 percent probability of suffering chronic lung disease or other effects of being born with immature organs.

Infants born between 22 and 23 weeks of gestation weighs below 600 grams and has a 30 to 50 percent chance of survival. Still, survival comes at a high price in quality of life.

Neonatal care practices have improved overall survival of premature infants and offer various solutions such as steroid injections, kangaroo mother cares or antibiotics to treat newborn infections. However, researchers at the Children’s Hospital of Philadelphia (CHOP) have decided to treat the infants more like fetuses than newborns and developed artificial womb.

Inside An Artificial Womb

The device works by two major components. First is a circulatory system that allows the baby to get oxygen through the blood (rather than through the lungs), just like in the womb. This is a process called oxygenation. The other component is a fluid environment. The fetus is enclosed in a heavy-duty bag filled with lab-made amniotic fluid. So, this system mimics life in the uterus as closely as possible.

The sealed, sterile environment inside the system is insulated from variations in temperature, pressure and light, and particularly from hazardous infections.

A diagram showing how the artificial womb-like ‘bio bag’ nourishes a fetal lamb Image credit: The Children’s Hospital of Philadelphia

The researchers took eight lambs between 105 to 120 days gestation (which is equivalent to 23 – 24 weeks for human babies) and placed them inside the artificial womb. After four weeks in the womb, lambs had normal growth, lung and brain maturation and they were able to wiggle.

The device in the fetal lamb experiment is kept in a dark, warm room where researchers can play the sounds of the mother’s heart for the lamb fetus and monitor the fetus with ultrasounds. One of the researchers called the device a “technological miracle” that marks “a huge step to try to do something that we’ve been trying to do for many years.”

The researchers will continue to evaluate and refine the system and will need to downsize it for human infants. In the future, the team hopes to see the device become an innovative solution used in neonatal intensive care units to support extremely premature infants.