Effects of epidermal growth factor in the final stages of nuclear and cytoplasmic oocyte maturation in humans

Evidence has accumulated in mammals suggesting a positive rolefor epidermal growth factor (EGF) as an inducer of oocyte maturation.The potential use of EGF as inducer of cytoplasmic and nuclearmaturation was tested in women with > 10 oocytes retrievedin in-vitro fertilization (IVF), since we have previously observedthat such oocytes are immature. Oocytes from 17 high responderswere randomly allocated to one of the three treatment groupsupon retrieval: control receiving no EGF (n = 93), 1.0 ng/mlEGF (n = 92) and 10.0 ng/ml EGF (n = 77) for 6 h before insemination.The rates of fertilization were respectively 54.6, 59.0, and46.1%, suggesting that EGF is not effective at this maturationalstage after this length of exposure. Embryo development wasfurther analysed by the appearance of the embryos under thedissecting microscope and the number of blastomeres developed48 h after insemination. No difference between groups was observedconsidering the number of blastomeres developed. However, embryosderived from oocytes treated with 10 ng/ml EGF displayed a worseappearance under the microscope. It is concluded that a 6 hincubation with EGF does not seem to affect cytoplasmic maturationin oocytes obtained after gonadotrophin treatment, as ascertainedby the rate of fertilization following oocyte insemination.