July 2, 2022

First pregnancy from frozen ovaries

A woman who underwent aggressive chemotherapy and radiotherapy has become pregnant naturally after fertility doctors reimplanted strips of her frozen ovarian tissue. The woman is now 24 weeks pregnant with a girl after treatment at the Catholic University of Louvain in Brussels, Belgium. This landmark technique offers the hope of renewed fertility for cancer patients, many of whom become infertile and menopausal after treatment for their illness.

Frozen ovarian tissue has produced embryos before, but only through IVF. This is the first time that a natural pregnancy has been achieved. Although researchers presented the technique as a way for younger women to beat cancer, it also prompted media speculation about women bypassing menopause by freezing ovaries in their 20s and having children in their 50s or 60s.

  

Cloning errors could affect cure potential for embryos

Cloning creates potentially dangerous abnormalities in embryos, scientists from Cornell University told the ESHRE conference. Only 30% of cloned mouse embryos reached the blastocyst stage of development, while the proportion of parthenogenetic and ICSI embryos was about the same as naturally conceived embryos, Takumi Takeuchi and Gianpiero Palermo found. The reason for this, they think, is that the gene activity in the cloning process is abnormal.

Although the researchers’ take-home message was that reproductive cloning is unsafe, the executive director of ESHRE, Professor Andre van Steirtegheim, also warned that these problems had to be solved before therapeutic cloning could be used to treat human diseases. “It would be a grave mistake, if there was something wrong with the epigenetics of these stem cell lines, to transfer them back into patients,” he said.