Last updated May 9, 2017 at 12:26 pm
An animal study has developed an extremely unique womb-like device for extremely premature lambs.
US researchers in Philadelphia have created an artificial womb capable of supporting the growth and development of premature animals. They hope that this technology could one day also help premature human babies. Details of this new technology were published in Nature Communications.
The system, trialled on extremely premature lambs, consists of a container filled with artificially created amniotic fluids which supply nutrients and support lung development. The lamb’s heart pumps blood through the umbilical cord into a gas exchange machine that replicates the functions of the mother’s placenta. Electronic monitors measure vital signs, blood flow and other crucial functions.
Schematic of the extracorporeal system for physiologic fetal support. Image credit: The Children’s Hospital of Philadelphia
There is no external pump to drive circulation because they found that even gentle artificial pressure can fatally overload an underdeveloped heart. Similarly there is no external ventilator because they found that the immature lungs are not yet ready to do their work of breathing in atmospheric oxygen.
The system used here was developed over three years through a series of four prototypes. With the latest version of this system the researchers were able grow six pre-term lambs from a developmental stage equivalent to 23- or 24-week-gestation human infants.
Previous attempts have been made to build an artificial placenta but pumpless systems have only achieved a maximum survival of 60 hours and the infants have sustained brain damage. This new system has operated for up to 670 hours (28 days) in some cases and the animals have remained healthy. The lambs showed normal breathing and swallowing, opened their eyes, grew wool, became more active, and had normal growth, neurological function and organ maturation.
The researchers say that, while there are still some barriers to adapting the system to humans, they will continue to refine the system with the hope of being able to help extremely premature human babies in the future. The researcher’s goal is to support infants from 23 weeks to 28 weeks when they cross a threshold away from the most severe outcomes. Interestingly, one barrier will be the need to shrink the system for human babies that are around one-third the size of the infant lambs used in this study.
In the US, extreme prematurity (younger than 26 weeks) is the nation’s leading cause of infant mortality and morbidity, accounting for one-third of all infant deaths and one-half of all cases of cerebral palsy attributed to prematurity. Current neonatal care practices have improved overall survival of premature infants and have pushed limits of viability to around 23 weeks. But this survival comes at a high price with a 90 percent risk of morbidity, from chronic lung disease or other complications of organ immaturity and survivors face lifelong disability.
- Brew Ha Ha – New Hope for Premmies
- Link to the Nature Communications article: https://www.nature.com/articles/ncomms15112