It may take more than just a healthy sperm and egg to produce a healthy baby. A new study indicates the health of a man’s seminal fluid is an indicator for ease of conception as well as life-long health of offspring. The editor of the paper generated by the study says “seminal fluid is not just a swimming pool for sperm.”

The study, led by senior author Sarah Robertson, used mice to determine if the absence of seminal fluid made a difference in conception and offspring health. Fluid produced in the seminal vesicle gland is secreted along with sperm during ejaculation. Congenital abnormalities of a seminal vesicle may impair its function, as could injury or disease suffered after birth.

Sperm and egg fertilization illustrationRobertson, a professor of reproductive health and pediatrics at Australia’s University of Adelaide, and her research team removed the seminal vesicle glands of mice so they could not produce seminal fluid. They tested the impact of the absence of seminal fluid in two ways:

  • By mating them with healthy female mice
  • By using the sperm of these mice to fertilize an egg that was then implanted and produced offspring

In the first group, the offspring conceived normally but without seminal fluid developed life-threatening health complications that included altered metabolism, hypertension, lowered glucose tolerance, and obesity. The male offspring of these matings were more likely to be adversely affected than the female offspring.

The group of mice born from the implanted embryos were more likely to experience problems associated with growth and metabolism than a control group of mice born from embryo implantation using sperm from male mice with intact seminal vesicles.

According to Robertson, seminal fluid contributes more to conception that transporting sperm to egg. “The seminal fluid also provides signals that promote the chances of pregnancy, by conditioning the female to produce growth factors that best support the early embryo.”

Seminal fluid may also be a factor in transmitting the genetic tendency toward obesity from one generation to the next, especially from men to their sons.

John Eppig, the report’s editor, suggests seminal fluid may play “an essential role in the preservation of sperm function and in the stimulation of the female reproductive tract.” Eppig is a Professor at the Jackson Laboratory in Bar Harbor, Maine.

Robertson calls for continued research on seminal fluid’s influence on conception, pregnancy, and health of offspring to determine if the effects found in the mice experiments carry through to humans. Anatomical differences between the species means less fluid reaches the higher parts of the reproductive tract in women than in mice. Nevertheless, the study seems to indicate the importance of conditions at the time of conception on the life-long health of the offspring regardless of species.

Source: Robertson, Sarah A, et al. “Maternal tract factors contribute to paternal seminal fluid impact on metabolic phenotype in offspring (pdf).” PNAS. Proceedings of the National Academy of Sciences of the United States of America. Jan 23, 2014. Web. Feb 6, 2014.