Select Page

Most people wouldn’t want to be infected by a parasitic worm.

But what if it helped you get pregnant?

Science journal recently released a study showing how parasitic worms can increase a woman’s chances of becoming pregnant. Lifelong infection by Ascaris lumbricoides, is associated with high fertility rates in a study of 986 indigenous women in Bolivia. The researchers, led by Prof. Aaron Blackwell, of the Department of Anthropology at the University of California-Santa Barbara (UCSB) assessed the prevalence of pregnancies of each woman had with the incidence of infection. They compared nine years of data, with two of the most common worms – giant roundworm and hookworm.

The study itself was initiated after unusual circumstances.  Melanie Martin is one of the authors from the Department of Anthropology at USCB. She became pregnant almost immediately after her arriving to Bolivia to investigate the worms in Bolivia with her husband.

These indigenous Tsimane Bolivian families are already quite large – nine children is the average. Parasitic worm infections are now suspected to have something to do with fertility, being that about 70% of the population has the infection.

So, what is the effect of the infection? How does it impact fertility?

According to Professor Blackwell, “The effects we see are probably due to these infections altering women’s immune systems, such that they become more or less friendly towards a pregnancy.”

The researchers also found that the length of intervals between births decreased.  Over one reproductive lifetime, the time between births was reduced for those with roundworm infection. So with roundworm, fertility is high: those chronically infected with roundworm have had as many twelve children.

Hookworm infection had the opposite effect, increasing birth intervals. Hookworm also causes delays in the first pregnancy.

The research is still new and shows merely association (not cause) between results.  However, down the road these findings are could lead to novel discoveries in fertility drugs.