Addition of granulocyte macrophage colony stimulating factor (GM-CSF) during in vitro oocyte maturation improves embryo development in a mouse model of advanced maternal age

Oocyte developmental competence declines in women aged 35 and older resulting in many women resorting to IVF. The present study determined whether adding Granulocyte-macrophage colony-stimulating factor (GM-CSF) during in vitro oocyte maturation (IVM) could improve oocyte developmental competence in a mouse model of advanced maternal age. Oocytes from 12-14 month C57BL6 J x CBA mice were treated with 10 ng/ml of GM-CSF during IVM, and embryo development, mitochondrial activity, spindle formation and chromosomal alignment were examined. The addition of GM-CSF tended to increase fertilisation rates (76.19 vs. 82.03%; P = 0.07) but did not affect cumulus expansion compared with control. The addition of GM-CSF also increased blastocysts rates (51.10 vs. 61.52%; P < 0.01) and the number of good quality blastocysts (33.31 vs. 44.13%; P < 0.05) present at 96 h of culture as well as inner cell mass (12.64 vs. 15.62 ; P < 0.01) and total cell number (42.98 vs. 48.78 ; P < 0.05). GM-CSF treatment also increased mitochondrial membrane potential two to three fold in the outer (2.86 vs. 0.97; P < 0.001), intermediate (3.25 vs. 0.89; P < 0.001) and peri nuclear areas (3.62 vs. 1.08; P < 0.001). GM-CSF treatment did not influence spindle formation or chromosomal alignment. Together our results indicate that the addition of GM-CSF during IVM may improve oocyte quality in women of advanced maternal age.