November 20, 2015

The worm that helps women get pregnant.

"A study of 986 indigenous women in Bolivia indicated a lifetime of Ascaris lumbricoides, a type of roundworm, infection led to an extra two children...."
Nine children is the average family size for Tsimane women in Bolivia. And about 70% of the population has a parasitic worm infection. Up to a third of the world's population also lives with such infections....


Professor Allan Pacey, a fertility scientist, said: "Whilst I wouldn't want to suggest that women try and become infected with roundworms as a way of increasing their fertility, further studies of the immunology of women who do have the parasite could ultimately lead to new and novel fertility enhancing drugs."

20 comments:

Curious George said...

They may also have had bigger titties.

mikee said...

Correlation not being causation, I'd look at other correlated factors associated with higher birth rate quite closely before suggesting parasitism as a way to get babies.

Just off the top of my head, living where more food is available, which might be where the parasite is also more prevalent, might explain both the higher rates of pregnancy and the correlation to the worms.

Or maybe the article has a point, and in our bold future we will be able to turn our reproductive systems on and off with GMO parasite tablets and worming pills.

Ann Althouse said...

I wonder if there's a worm that makes people say "whilst."

rehajm said...

The one at the bottom of the tequila bottle works, too.

tim maguire said...

What mikee said. I'm betting these women have a lot more in common than just tapeworms.

Fernandinande said...

Helminthic therapy: using worms to treat immune-mediated disease.

jaydub said...

Reported opposite effects of hookworm are equally interesting. In fact, Sandra Fluke is now demanding that hook worms be added to the birth control options under Obamacare.

Unknown said...

where's laslo?

Rick said...

Correlation not being causation, I'd look at other correlated factors associated with higher birth rate quite closely before suggesting parasitism as a way to get babies.

Maybe parasites keep them thinner increasing desire from both parties.

Plenty of possibilities, the idea that this is some breakthrough is quite premature from a scientific standpoint. Of course if your goal is to generate buzz leading to government funding the timing makes complete sense.

wildswan said...

The people who did this study wanted to study the heath history of people who did not have modern medicine so as to create a baseline for the health effects of modern medicine. To gain access to the Tsimane people and to gain their trust the study agreed to send in primary care physicians or physicians assistants. This would have ruined the study because primary care physicians would have treated the parasitic infections and attempted to locate infection vectors and warn against them as soon as the study found how widespread they were. But cleverly the study found that the presence of the promised primary care workers made no difference as long as they did not use antibiotics on a wide scale. And, of course, they did not attempt to clean up the water or whatever was spreading the parasites. In other words they did not treat chronic conditions, only accidents. So by this they were able to show that parasites were widespread in the era before modern medicine and they were able to document such effects as stunting both physical and mental. And fertility as a consequence of another parasitic infection. Thank you, Tsimane people - so sorry you didn't get decent help as you expected but some great research papers have propelled careers as a result of your untreated infections.

The Tsimane study, a worthy heir to the Tuskegee syphilis study was also supported by eugenic society members, including Eileen Crimmins, an PhD and a Professor at USCD and director of the USC/UCLA Center on Biodemography and Population Health. Biodemography is the new form of eugenics and the society of Biodemography and Social Biology of which Crimmins is a director and editor of its journal is the direct heir of the American Eugenics Society.

lgv said...

Cause and effect not established. Makes great short articles on the internet.

phantommut said...

I have a feeling there's a strong chance we have a confusion between correlation and causation problem here. (Nuts, mikee beat me to it.)

BarrySanders20 said...

Parasites: the original microaggressors.

dbp said...

If I had to guess the correlation between the worm and fertility, it would go like this: Poor rural woman tend to have more children than rich urban women--independent of worms. Poor rural women are out in fields and jungles while better off women are at home or have office jobs. There are more opportunities to contract worms in the former locations.

buwaya said...

"Nine children is the average family size for Tsimane women in Bolivia. "
They are doing something right.
The future belongs to them, for better or worse.

Ann Althouse said...

Thanks, wild swan. That was important.

jimbino said...

Helminths can be beneficial: http://www.medicaldaily.com/they-might-sound-gross-intestinal-worms-can-actually-be-good-you-359794

If you want to treat a helminth infestation with mebendazole, you can either pay a fortune for a doc visit and prescription drugs (usually 3 pills) in the USSA or get them free or almost free in places like Brazil and Mexico.

Sayyid said...

Er, isn't it more probable that the causation would run the opposite way? I.e., women who get pregnant more than average are more prone to infection by that species of roundworm? Remember, all they've actually done here is correlate number of pregnancies and infection by this roundworm. Not establish which way any causal link would run.

I don't have a medical background, but it seems to me that giving birth would have an infection risk...

The Godfather said...

"Prof Allan Pacey, a fertility scientist at the University of Sheffield, [said]: 'Whilst I wouldn't want to suggest that women try and become infected with roundworms as a way of increasing their fertility . . . .'"

I really like that Brits say "whilst", but for gosh sakes he means he wouldn't suggest that "women try TO become infected", not "women try AND become infected". Don't we and the Brits educate scientists in proper English grammar? I hear Henry Higgens now.

ken in tx said...

Oh, stop whinging about whilst.