Intestinal helminths results in increase of woman’s fertility

Findings of a new study are suggesting that infection caused by a parasitic worm called Ascaris lumbricoides can make a woman more fertile. A study involving 986 indigenous Bolivian women indicated that a lifetime of the parasitic infection resulted in two extra children.

The study, which was eventually published in the journal Science, suggested that the worm is capable of altering a woman’s immune system and make it much easier for her to get pregnant. This finding, according to experts, might lead to the formulation of new fertility enhancing drugs.

An average Tsimane woman in Bolivia gives birth to around nine children, and the study showed that nearly 70% of these women have Ascaris lumbricoides infection. Such infections have also been found in as much as one-third of the global population.

While scientists saw Ascaris lumbricoides increase women’s fertility during the course of the nine-year research, they also witnessed hookworms producing the opposite effect. A lifetime of hookworm infections were found to result in three fewer children.

University of California’s Professor Aaron Blackwell, a coauthor of the study, said that the effects observed during the study are unexpectedly big. Prof. Blackwell added that the immune system of a woman changes naturally when she gets pregnant to ensure that her body doesn’t reject the fetus. According to him, the effects showcased by the parasitic worms are triggered due to the infections changing the pregnant woman’s immune system making her less or more prepared for a pregnancy.

Blackwell believes that using parasitic worms for treating infertility is quite an intriguing possibility. However, he has also cautioned that more work needs to be done before using any such treatment option.

Immune system and parasitic worm specialist Professor Rick Maizels said that the fact that effects of hookworms are so intense is a matter of big concern. He added that 50% women aged between 26 and 28 years who are yet to get pregnant have hookworm infection, which makes the worm’s ability of reducing fertility a bigger issue.

Viral and bacterial infections try outpacing our immune system by inducing explosive population growth. Prof. Maizels explained that the parasites do exactly the opposite; they tend to grow slowly and try to suppress our immune system. This is the reason why parasitic worms make vaccines less effective and reduce the intensity of allergies.