Reproduction Abstracts

Since the advent of IVF (in vitro fertilisation), several million babies have been born worldwide. However, reports link in vitro techniques with adverse short and long-term health outcomes. Using a mouse model, we investigated the effect of IVF and duration of culture on blastocyst development and cell number and the postnatal health of offspring. Experimental groups (8–13 litters each): NM (natural mating, non-superovulated) IV-ET-2Cell (2-cell embryos derived in vivo from superovulated mothers (SOM) and immediately transferred (ET) to recipients IV-ET-BL (blastocysts derived in vivo from SOM and immediate ET) IVF-ET-2cell (2-cell embryos generated by IVF from SOM, short culture and ET) IVF-ET-BL (blastocysts generated by IVF from SOM, long culture and ET). IVF blastocysts after prolonged culture developed slower and comprised reduced trophectoderm and ICM cell numbers compared with in vivo generated blastocysts (P<0.05 n=50–87 per treatment). IV-ET-2Cell (n=57), IV-ET-BL (n=47), IVF-ET-2Cell (n=75) and IVF-ET-BL (n=42) groups compared with NM controls (n=80), showed increased body weight, increased SBP, impaired GTT and abnormal organ:body weight ratios in both genders (P<0.05), independent of litter size. At weeks 15, 21, SBP for IVF-ET-BL males was increased compared to IV-ET-BL and IVF-ET-2Cell males. However, glucose concentration 2 h after glucose injection and AUC (area under curve) in male IVF-ET-BL was reduced compared with IVF-ET-2Cell males. Serum insulin for IVF-ET-BL males was significantly reduced compared with IVF-ET-2Cell, but serum glucose and G:I ratio did not show any significant differences. No differences were evident between the four treatments groups for females. We conclude that reproductive treatments affect the development and potential of preimplantation embryos, influencing postnatal development and physiology compared with undisturbed reproduction. In particular, duration of embryo culture, with normalised SO, IVF and ET, may affect male offspring cardiometabolic health and organ allometry but female health is less sensitive.