In vitro maturation of oocytes (IVM) represents an assisted reproductive technique that involves the minimal or absence of ovarian stimulation and is beneficial to specific groups of patients. These may include women with polycystic ovarian syndrome and/or patients who need a fertility preservation option before undergoing gonadotoxic treatment. However, when IVM is applied in cases where it is not recommended, it can be considered as an add-on technique, as described by the ESHRE Guideline Group on Female Fertility Preservation. Interestingly, IVM has not been proven yet to be as effective as conventional IVF in the laboratory, in terms of clinical pregnancy and live birth rates, while concerns have been raised for its long-term safety. As a result, both safety and efficacy of IVM remain still questionable and additional data are needed to draw conclusions.

The effects of hormone additions at various stages and different basic media, with or without serum, on porcine oocyte maturation in vitro were studied. The results showed that the rate of maturation was not significantly different with three different stages of hormone supplement; the rate of maturation on modified TCM199 medium (54.01%) was higher than that on TCM199 (46.16%) and (47.14%), but these differences were not significant; and the rate of maturation on serum-free medium (67.10%) was significantly higher than that on medium plus serum (52.22%). Therefore, modifed tissue culture medium 199 (mTCM199)+10I U/ml pregnant mare serum gonadotrophin (PMSG)+10I U/ml human chorionic gonadotrophin (hCG)+2.5 IU/ml follicle stimulating hormone (FSH) was a suitable medium for culture of porcine oocytes in vitro, and the rate of maturation was 67.10%.