As we reported earlier, a recent study suggested that there was a link between a parasitic roundworm and an observed increase in fertility among the women in the Tsimane population in Bolivia. A study from the University of California-Santa Barbara found that women who were infected with roundworm had more children on average than women who did not have the parasites.

The study, which was published in the journal Science and led by UCSB anthropologist Aaron Blackwell, reveals that there may be a connection between the presence of parasites and the capabilities of the immune system. This link was apparent when researchers noticed a correlation between parasite infections and fertility rates within the Tsimane population.

According to Blackwell, roundworm infections can lead to increased immune system activity, which often results in a higher survival rate for babies born from mothers who are infected with the parasite.

While Professor Blackwell warns against a hasty adoption of using the nematodes deliberately to increase fertility, further research on the subject may yield a greater understanding into how the immune system functions and what this means for pregnant women around the world.

Researchers have tried a number of treatments in hopes of enhancing fertility, but few have proven successful to date. Roundworms are the first parasites that have been found to increase fertility, and could result in a class of medications that would improve the chances of conceiving without having to attach a live parasite to one’s body.

People infected with roundworms often show no symptoms, and rarely realize that they have been infected in the first place. The study found that women infected with helminth roundworms had elevated levels of immunoglobulin E, which appears to have had an effect on the general well-being of pregnant women and their children.

A press release from the University of California – Santa Barbara outlining the details of the study can be found here.