In vitro maturation of ovarian follicles

Kirsty Horsey

Progress Educational Trust

03 July 2003

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[BioNews, London] A study presented at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE) conference in Madrid, Spain, has suggested a future way of harvesting eggs from aborted fetuses. Researchers from Israel and the Netherlands presented the results of a preliminary study into the feasibility of maturing and developing ovarian follicles retrieved from aborted fetuses.

Research team leader, Dr Tal Biron-Shental, from Meir Hospital in Kfar Saba, Israel, recognised that taking egg follicles from an aborted fetus was controversial: 'I'm fully aware of the controversy about this - but probably, in some place, it will be ethically acceptable', she said. She added, 'there is a shortage of donated oocytes [eggs] for IVF. Oocytes from aborted foetuses might provide a new source for these. There are a huge amount of follicles in the foetal ovary.'

The aim of the research was to study the development of ovarian follicles in a laboratory setting, with a view to the potential clinical use of eggs from those follicles if the technique can be perfected. If successful, the work may go some way to solving the problem of the shortage of donated eggs for use by infertile patients or in medical research. For now, however, the team is only involved in basic research.

With the informed consent of the woman involved, researchers took ovaries from aborted fetuses of between 22 and 33 weeks gestation. After storage, follicles from the fetal ovarian tissue survived in a growth-promoting culture for up to four weeks and showed some signs of maturing. The research points to the potential for culturing fetal tissue in vitro in order to mature the eggs which the tissue contains. Dr Biron-Shental said that although some of the follicles had developed to be healthy and viable, further research is needed, including making improvements in the chemicals used to culture the tissue.

Another paper presented at the same session of the ESHRE conference shows promise for the development of in vitro maturation (IVM) of eggs. IVM is a technique that could be useful for fertile women undergoing IVF because their partners have impaired sperm or for women with polycystic ovarian syndrome (PCOS). PCOS is a common form of ovarian dysfunction caused by an imbalance in sex hormones. Women with the syndrome are susceptible to developing ovarian hyperstimulation syndrome (an excessive ovarian response to IVF hormones which, in extreme cases, can be life-threatening) during fertility treatment.

Dr Anne Mikkelsen, a consultant at the Herlev Fertility Clinic, Denmark, presented the results of a follow-up study of babies born following IVM (in vitro maturation). The eggs were matured in vitro for between 28 to 36 hours and then fertilised by intracytoplasmic sperm injection (ICSI). Thirty-three babies were born, one of which did not survive, and one had a soft cleft palate. Developmental tests were performed on 18 of the children at six months, one year and two years old and they will be examined again when they are five. All of the children were developing well. Dr Mikkelsen commented that more IVM children will have to be born before any definitive conclusions can be drawn, adding however, these results indicate that the IVM method seems to be safe.

Reproduced with permission from BioNews, an email and online sources of news, information and comment on assisted reproduction and genetics.