Santa Barbara, California – A parasitic worm infection found in the Tsimane women of Bolivia may increase the fertility rate.

These women have been reported as the most fertile around the world -as they have an average of 10 children in their lifetimes-, an assumption that lead researchers from the University of California to investigate this phenomenon.

Tsimane family that live in the Bolivian Amazon. Credit: Adrian Jaeggi

The research team collected and analyzed information from nearly 1,000 women in this Bolivian community over the course of nine years, and found that women who were infected with roundworm had up to 12 children. On the other hand, women chronically infected with hookworm infection dropped the numbers down to seven children.

Although these infections are highly common, and in most cases people don’t suffer any symptoms, they can lead to respiratory issues, fever, anemia and, in some cases, to fatal complications.

Aaron Blackwell, lead author of the study, explained that these effects could be related to the balance of several immune system responses that the different worm infections produce in the woman’s body. Blackwell told the BBC that these immune shifts can make a woman’s body more propense towards pregnancy.

Experts in the fertility field stated that these findings could improve In Vitro Fertilization (IVF) by developing new means and treatment for those women showing troubles to getting pregnant in the future. Nevertheless, they warn that, under no circumstances, women shouldn’t try to increase their possibilities by getting self-infected with roundworms.

Professor Rick Maizels, a specialist in parasitic worms, said to the BBC, “It’s horrifying that the hookworm effects are so profound, half of women by 26 or 28 have yet to fall pregnant and that’s a huge effect on life.”

Researchers have stated that these results are only preliminary, as they only show an association and not quite yet a causal relation. Further research is needed in order to study how this mechanism could take place and decide if it is viable for implementation. In the past, drugs have been developed to alter a woman’s immune system to boost IVF effects, without success.

Source: Science Magazine