Link Between Parasitic Worm and Female Fertility

A new study has uncovered a surprising link between parasitic infections and a woman’s fertility rate, finding that while a few infections compromised a woman’s fertility, others seemed to increase it.

They said that the average Tsimane woman had nine children but that those infected with the Ascaris would tend to bear two more than those not infected.

The researchers made a decision to embark on their study after one of the authors Melanie Martin – also of the Department of Anthropology at UCSB – fell pregnant while investigating parasitic worms with her husband in Bolivia.

Researchers have conducted a study on 986 indigenous women in Bolivia, where the average family size is of a whopping nine total members.

Researchers from the University of California Santa Barbara studied the effects of infection with roundworm and hookworm, each of which appeared to have a different effect on the number of pregnancies in women in the native population.

The report, “Helminth infection, fecundity and age of first pregnancy in women”, discusses a long term study of ways that parasites, specifically roundworms and hookworms living in Tsimane women, affect the ability of the women to reproduce. They found that Tsimane women afflicted with roundworms were more likely to have two additional children.

Another fertility scientist, professor Allan Pacey at the University of Sheffield, said the results could lead to new drugs for women wanting to become pregnant.

Intestinal worm infections are common, affecting more than 1 billion people, and are particularly prevalent in tropical areas with poor sanitation.

Prof Aaron Blackwell, one of the researchers, told BBC News: “The effects are unexpectedly large”.

In conclusion, parasites are not all bad, and especially if you’re a woman who’s trying to get pregnant, you might think twice before saying “ew!”. About 70% of the women in the population has a parasitic worm infection.

Despite the repulsion often felt towards parasites, they have a lot in common with a developing human foetus. Generally, it’s been thought that parasites, worms included, can weaken people, and aside from causing diarrhea and abdominal pain, could also make it harder for infected women to bear child. This worm was found to increase the fertility and the hookworms decrease the same. Women are likely to conceive as their immune system has fewer chances to reject the fetus after they are infected with the worm.