London, February 14
Doctors are developing artificial wombs in which embryos can grow outside a woman's body. The work has been hailed as a breakthrough in treating the childless.
Scientists have created prototypes made out of cells extracted from women's bodies. Embryos successfully attached themselves to the walls of these laboratory wombs and began to grow. However, experiments had to be terminated after a few days to comply with in-vitro fertilisation (IVF) regulations.
"We hope to create complete artificial wombs using these techniques in a few years," said Dr Hung-Ching Liu of Cornell University's Centre for Reproductive Medicine and Infertility in New York. "Women with damaged uteruses and wombs will be able to have babies for the first time."
The pace of progress in the field has startled experts. Artificial wombs could end many women's childbirth problems — but they also raise major ethical headaches which will be debated at a major international conference titled "The End of Natural Motherhood?" in Oklahoma next week (February 22 and 23).
"There are going to be real problems," said organiser Dr Scott Gelfand, of Oklahoma State University. "Some feminists even say artificial wombs mean men could eliminate women from the planet and still perpetuate our species. That's a bit alarmist. Nevertheless, this subject clearly raises strong feelings."
Liu's work involves removing cells from the endometrium, the lining of the womb. "We have learnt how to grow these cells in the laboratory using hormones and growth factors," she said.
After this Liu and her colleagues grew layers of these cells on scaffolds of biodegradable material which had been modelled into shapes mirroring the interior of the uterus. The cells grew into tissue and the scaffold dissolved. Then nutrients and hormones such as oestrogen were added to the tissue.
"Finally, we took embryos left over from IVF programmes and put these into our laboratory engineered tissue. The embryos attached themselves to the walls of our prototype wombs and began to settle there."
The experiments were halted after six days. However, Liu now plans to continue with this research and allow embryos to grow in the artificial wombs for 14 days, the maximum permitted by IVF legislation. "We will then see if the embryos put down roots and veins into our artificial wombs' walls, and see if their cells differentiate into primitive
organs and develop a primitive placenta.” The immediate aim of this work is to help women whose damaged wombs prevent them from conceiving. An artificial womb would be made from their own endometrium cells, an embryo placed inside it, and allowed to settle and grow before the whole package is placed back in her body.
“The new womb would be made of the woman’s own cells. so there would be no danger of organ rejection,” Liu added.
A different approach has been taken by Yoshinori Kuwabara at Juntendo University in Tokyo. His team has removed foetuses from goats and placed them in clear plastic tanks filled with amniotic fluid stabilised at body temperature.
In this way, Kuwabara has kept goat foetuses alive and growing for up to 10 days by connecting their umbilical cords to machines that pump in nutrients and dispose of waste.
Observer News Service
