Scientists get a step closer to producing babies from stem cells
The dream of in vitro gametogenesis is getting closer , but scientists and ethicists will have to wait decades before it becomes a reality
One of the most exciting — and ethically challenging — concepts in reproductive medicine has been given a boost after Japanese scientists managed for the first time to artificially form eggs wholly from stem cells that would go on to be fertilised and gestated into newborn mice .
By doing so , they have crossed another frontier on the way to achieving in vitro gametogenesis ( IVG ), a longstanding ambition to create offspring from artificial eggs and sperm .
Until recently , sperm could only be made inside a testis and eggs from an ovary . A decade ago , Dr Hayashi Katsuhiko of Kyushu University was the first to produce functional mouse sperm from stem cells , and in 2016 , he produced the first functional eggs in mice , although these required fresh ovarian tissues taken from mice to enable them to mature . In his latest experiment , Professor Hayashi successfully recreated this ovarian support tissue to give rise to viable , eggproducing ovaries .
These could then be used in human assisted pregnancy for infertile heterosexual and same-sex couples with each partner being a genetic parent to their children . It could also even allow women to become pregnant without the
need for a third-party donor .
Given that the research only represents a very early breakthrough , scientists believe it will make it easier to study the causes of infertility and provide an alternative source of gametes , or reproductive cells , for research .
While scientists have been seeking ways to achieve IVG , ethicists have been considering the moral suitability of the approach .
In a commentary written in Science Translational Medicine , three Harvard scientists argued : “ While IVG carries a promise to unravel the fundamental mechanisms of devastating genetic forms of infertility and to pave the way to a range of new therapies , the technique also raises a number of vexing legal and ethical questions that society should address before IVG becomes ready for prime-time clinical use in human patients .”
Using IVG to allow infertile heterosexual couples to have genetically related children has generally been accepted by bioethicists . Other potential clinical applications , such as enabling same‐sex reproduction , postmenopausal motherhood , and solo genetic parenthood have attracted significantly more criticism . IVG also raises the potential for eugenics , or selective breeding , to enter the mainstream .
“ There ’ s something considerably worrying about allowing an infinite supply of gametes that can be used as an inexhaustible supply of embryos ,” Nor Azlina Mohamed , a bioethicist at the University of Malaya , told Global Health Asia-Pacific .
“ It could be said that IVG could enable the selection of embryos that have desired traits , but even though the creation of so-called designer babies is worrying , it ’ s a separate issue altogether to the moral acceptability of IVG , which would potentially be beneficial for couples who cannot conceive on their own but who want to have their own genetic offspring ,” she said .
In the meantime , it looks like ethicists , lawyers , and regulators will have plenty of time to formulate their responses to the idea of IVG . Experts believe it will be decades before Professor Hayashi ’ s latest findings are developed into something workable , and that ’ s assuming it can be practically translated from mice into humans . In the meantime , he ’ s continuing his research on marmoset monkeys . As he told STAT : “ The issue is the quality of the in vitro oocyte ( egg ). That could take a long , long time to verify .”
32 OCTOBER 2021 GlobalHealthAsiaPacific . com