Artificially ‘growing’ lambs using unique womb design
27 April 2017
A unique womb-like environment designed by pediatric researchers successfully grew a baby sheep and could transform care for extremely premature babies.
The research was carried out at the Children’s Hospital of Philadelphia and mimics the prenatal fluid-filled environment to give premature babies precious extra weeks to develop their lungs and other organs.
“Our system could prevent the severe morbidity suffered by extremely premature infants by potentially offering a medical technology that does not currently exist,” said study leader Alan W. Flake, a Fetal Surgeon and Director of the Centre for Fetal Research in the Centre for Fetal Diagnosis and Treatment at Children’s Hospital of Philadelphia (CHOP).
Flake and colleagues report on preclinical studies of their extra-uterine support device in Nature Communications. They tested and monitored effects on fetal lambs, in which prenatal lung development is very similar to that occurring in humans.
How does it work?
The system uses a fluid-filled container attached to machines that provide physiologic support. The fetal lambs grow in a temperature-controlled, near-sterile environment, breathing amniotic fluid as they normally do in the womb, their hearts pumping blood through their umbilical cord into a gas exchange machine outside the bag. Electronic monitors measure vital signs, blood flow and other crucial functions.
In addition, lab-produced amniotic fluid flows in and out of the bag. “Fetal lungs are designed to function in fluid, and we simulate that environment here, allowing the lungs and other organs to develop, while supplying nutrients and growth factors,” said Fetal Physiologist Marcus G. Davey, PhD, who designed and redesigned the system’s inflow and outflow apparatus.
Eight preterm lambs were tested in the most recent prototype and were physiologically equivalent to a 23 or 24 week-gestation human baby. The system operated up to 670 hours (28 days) and the animals remained healthy. After the trials, the lambs showed normal breathing and swallowing patterns and opened their eyes, grew wool, became more active and had normal growth.
The researchers will continue to evaluate and refine the system, and will need to downsize it for human infants, who are one-third the size of the infant lambs used in the current study.
For more information, visit the Children’s Hospital of Philadelphia website.
Video courtesy of the Children’s Hospital of Philadelphia