Want to Get Pregnant? Have More Sex!

It may seem pretty obvious but for years, fertility specialists suggested that couples refrain from too much sex to give sperm a chance to regenerate.

Now a new study is showing the complete opposite. 

According to newswise.com, sexual activity causes immune system changes that increase chances of conception.

Here's how it works: sexual activity triggers physiological changes in the body that increase a woman’s chances of getting pregnant, even outside the window of ovulation.

It's a common recommendation that partners trying to have a baby should engage in regular intercourse to increase the woman’s changes of getting pregnant -- even during so-called 'non-fertile' periods -- although it’s unclear how this works, researchers say. "This research is the first to show that the sexual activity may cause the body to promote types of immunity that support conception," says lead author Tierney Lorenz, a visiting research scientist at the Kinsey Institute. It’s a new answer to an old riddle: How does sex that doesn’t happen during the fertile window still improve fertility?

"It's a common recommendation that partners trying to have a baby should engage in regular intercourse to increase the woman’s changes of getting pregnant -- even during so-called 'non-fertile' periods -- although it’s unclear how this works," Lorenz said.

A few earlier studies show changes in immune function during pregnancy and after childbirth and changes in immunity across the menstrual cycle. But the Indiana niversity research is the first to show that sexual activity plays a role in these changes with clear differences found in immune system regulation in women who are sexually active versus women who are sexually abstinent, the web site reports.

Lorenz and colleagues have reported in the past that sexually active women experienced greater changes in helper T cells, and the proteins that T cells use to communicate. In this second paper, they report differences in antibody levels between the two groups.

Helper T cells manage the body's immune response in part by activating the cells that destroy invading microbes in the body. The antibodies -- also known as immunoglobulins -- are secreted by white blood cells and play an important role fighting off foreign invaders in the body.

There are several types of helper T cells and immunoglobulins. Type 1 helper T cells assist the body with defense against outside threats. Type 2 helper T cells help the body accept those aspects of pregnancy the body may otherwise interpret as "foreign invaders," such the presence of sperm or emerging embryo.

Similarly, immunoglobulin A antibodies -- typically found in the mucous of the female reproductive tract -- can interfere with the movement of sperm and other aspects of fertilization. Immunoglobulin G antibodies -- typically found in the blood -- fight disease without interfering with the uterus.

Shifts in immunity were found in sexually active women while they were not in abstinent women, Lorenz and colleagues found, perhaps aiding in conception.  .

"We're actually seeing the immune system responding to a social behavior: sexual activity," Lorenz says. "The sexually active women's immune systems were preparing in advance for the mere possibility of pregnancy."

So men and women who want babies, get crackin'!