Since 1997 doctors at the Fertility Clinic in Herlev, Denmark, have been helping women to have babies using a technique called in vitro maturation. This involves taking immature oocytes (eggs) from the women's ovaries and maturing them in the laboratory for between 28 and 36 hours. Then the oocytes are fertilised using intracytoplasmic sperm injection (ICSI) and the resulting embryos are transferred to the women's wombs.
IVM is a useful procedure for two groups of women: those who are fertile, with normal cycles, who don't need stimulating hormones to help them to become pregnant, but who are undergoing IVF because their partners have impaired sperm; and for women with polycystic ovarian syndrome[1] who are at an increased risk of developing ovarian hyperstimulation syndrome[2] during IVF hormone treatment.
Between July 1998 and January 2002, 33 children have been born after IVM had been carried out at the Herlev Fertility Clinic. Before then only seven IVM children had been born worldwide. However, until now there has been no evidence to show whether babies born after IVM are healthy and functioning normally – an important parameter for the quality of the technique.
Dr Anne Lis Mikkelsen, a consultant at the Fertility Clinic, said: "The advantage of maturing the oocytes in vitro is that you eliminate the risk of ovarian hyperstimulation syndrome. We collect the oocytes from 5-10mm follicles and mature the oocytes in vitro for 28 to 36 hours. In women with a regular cycle we perform IVM to time in with their natural cycle and we don't need to give them any extra hormones. In patients with polycystic ovarian syndrome we perform IVM after a short, three-day stimulation of the ovaries with follicle stimulating hormone. The duration of the treatment is very short, as we can collect the oocytes on days 8-10 in the cycle, thus reducing the risk of OHSS developing."
Of the 33 babies born after IVM, 16 were girls and 17 were boys. One girl was born dead, but her death was thought to be related to the failure of the placenta to operate properly rather than to the nature of her conception. Another girl had a soft palate, but with this exception all the children were healthy.
Dr Mikkelsen said: "The gestational age, birth weight, mode of delivery and Apgar score were reported for all babies. Furthermore a paediatrician examined the first 18 children when they were six months, one and two years old. The evaluation included an interview with the parents, a general examination, a psychometric examination and a developmental screening test[3]. The children are aged between two and four years old now, and are achieving higher than average scores in their developmental tests. This is probably a result of the parents' exceptional motivation."
The first 18 children will be examined by the paediatrician again when they are five.
Dr Mikkelsen concluded: "This is still a small study and more IVM children have to be born before we reach any definitive conclusion. However these results indicate that the IVM method seems to be safe."
Abstract no: O-014 (Monday 11.15hrs CET Auditorium B América)
Notes
[1] Polycystic ovarian syndrome (PCOS) is the commonest cause of ovarian dysfunction in women in the reproductive phase of life. The ovaries become enlarged with multiple, fluid-filled cysts. It is thought to be caused by an imbalance of sex hormones and can reduce fertility. Women with PCOS are very susceptible to developing ovarian hyperstimulation syndrome during fertility treatment.
[2] Ovarian hyperstimulation syndrome (OHSS) is the excessive response of the ovaries following the production of a large number of follicles during IVF hormone treatment. Severe OHSS can cause death.
[3] The Denver developmental screening test examines physical and intellectual development.
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