Experimental Study On The Culture Of Immature Human Oocytes In Vitro

Objective: To establish the culture system of human immature oocytes in vitro maturation(IVM); To evaluate the clinical application of IVM in the treatment of infertility women with polycystic ovarian syndrome(PCOS) and to investigate the effect and influencing factors of IVM.Methods: 39 PCOS patients who accepted in vitro fertilization and embryo transfer (IVF-ET) in Guangxi medical college third affiliated hospital, reproduction medical treatment centre of second people hospital of Guangxi Nanning province from 2006 August to 2007 September were enrolled in the study, who voluntarily choice IVF/ICSI or IVM technology under the situation of understanding the two technologies thoroughly. According to their choices, the patients were divided into IVF/ICSI group and IVM group. In IVM group, patients were stimulated with low dose Gn, then adopt immature oocytes in vitro culture 28 hours, after 3 days of ICSI, accepted embryo transfertation. In IVF/ICSI group, after patients accepted long proposal of disipidin adjusting and routine manipulating superovulation, harvest their mature ovums, then fertilize with IVF or ICSI and transfer in the third day. Compared the dosage of Gn, the level of E₂ on the day of HCG injection, the number of ovums, fertilization rate, cleavage rate, plant rate, clinical pregnancy rate, abortion rate and ovarian hyperstimulation syndrome (OHSS) rate.Results: 123 immature ovums were obtained in IVM group, after 28 hours of culture, 100 oocytes developed to M II stage, the maturing rate is 81.30%. Compared to IVF/ICSI, the dosage of Gn in IVM group is obviously lower(P<0.01), both the level of E₂ on the day of HCG injection and the number of ovums are lower(P<0.05). The high-quality embryo formation rate in IVF/ICSI group is higher(P<0.05). Although the plant rate of IVM group(8.33%) is lower than that of IVF/ICSI group(22.41%), the different is not distinct(P>0.05). There were no OHSS and abortion occurred in IVM group, but 3 in IVF/ICSI group respectively, the OHSS rate and abortion rate were 10.71% and 30%, these difference had no statistical significant(P>0.05).Conclusions: Immature human ovum have the ablilty to mature in vitro,develop into earlier embryos and gain clinical pregnancy. The culture system of immature oocytes in vitro maturation(IVM) is established through this study. IVM technology decreased the exogenous Gn dose of PCOS patients, so that both the number of follicle and the level of E₂ were decreased, which avoided or degraded the risk of OHSS, and developed a new way for the treatment of PCOS. The effect and influencing factors of IVM are very much,some factors are very important,such as: the use of Gn and HCG; the level of hormone on the day of HCG injection; the composition of culture solution and the culture time; the modality of fertilization.