Paternal diet-induced obesity impairs embryo development and implantation in the mouse

OBJECTIVE: To use a rodent model of male diet-induced obesity (DIO) to examine resultant preimplantation embryo development and implantation rate, as well as fetal and placental growth. DESIGN : Experimental animal study. SETTING: University research facilities. ANIMAL(S): C57BL/6 male and CBAxC57BL/6 female mice. INTERVENTION(S): Male mice were fed a standard rodent chow (lean) or a high-fat diet (obese) for up to 13 weeks. After mating, zygotes were collected and cultured to the blastocyst stage, then assessed or transferred into recipient females. MAIN OUTCOME MEASURE(S): Embryo morphology and cell number were assessed and pregnancy outcomes determined at postmortem day 18. RESULT(S): Embryos from obese males had reduced cleavage and decreased development to blastocyst stage during culture relative to control males. Blastocysts from obese males implanted at a reduced rate, and the proportion of fetuses that developed was significantly decreased, although fetal and placental weight did not differ between groups. CONCLUSION(S): This study demonstrates that paternal obesity impairs preimplantation embryo development and implantation but does not influence gross fetal or placental morphology. It highlights the important contribution that paternal health and lifestyle choices have for achieving a viable pregnancy.Megan Mitchell, Hassan W. Bakos and Michelle Lan