A father’s obesity negatively impacts sperm, which results in smaller fetuses, poor pregnancy success and decreased placental development, according to a team of experts at the University of Melbourne’s Department of Zoology.

The study urges men to get ‘match fit’ before getting their women pregnant to help with fetal development. Scientists are now encouraging men to shape up, even though health risks of obesity and pregnancy are usually focused on overweight moms.

According to estimates from the World Health Organization (WHO), 75% of Australian adult males are overweight or obese, which significantly exceeds the global average rate of 48%.

The research, led by Professor David Gardner, Dr. Natalie Hannan and Ph.D. student Natalie Binder, will be presented at the Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2012, starting August 26 to 29 on the Gold Coast.

Professor Gardner said:

“Australia has a weight problem; the rate of obesity among men of reproductive age has more than tripled in the last three decades. A lot of men don’t understand what contribution they’re having, but they need to be healthy before conceiving. Sperm needs to be match fit for the games of life and creating life is the biggest thing that we can do.”

In order to identify the effects of paternal obesity on embryo implantation into the mother’s womb and fetal development, in vitro fertilization (IVF) was used on animals in the study.

Embryos were generated from male mice that were normal weight and obese. For ten weeks, the obese mice were fed the equivalent of a western fast food diet.

Results showed that the fetuses produced from obese fathers had delayed development. There was about a 15% decrease in fetal development and the rate of embryo implantation in the womb.

Embryos derived from the sperm of obese men had significantly less placental weight and development.

According to the findings, having an obese father negatively affects embryo development and has a negative impact on the successful implantation into the womb.

A small placenta results from this, according to Binder, which impairs fetal growth and development with life long health consequences for the offspring.

Authors conclude:

“Our study provides more information about the impact of obesity in men and their ability to start a family and the need to shed kilos in preparation to conceive.”

Written by Sarah Glynn