寄生虫,女性生育能力 z-bo 2020-09-21 352

　　Can parasites benefit you? A recent study published in the journal Science found that certain types of infections seem to reduce women's fertility, but there is evidence that women infected with roundworms give birth to more children.

　　The Chisman indigenous people living in the Bolivian Amazonian Reserve look like this. They rarely use contraceptives, and each woman gives birth to nine children on average. A very common parasite called the worm small intestine in this area infects 70% of the population.

　　To study how these parasites affect fertility, Aaron Blackwell of the University of California, Santa Barbara and colleagues collected data on 984 women over a period of 9 years. Their project was inspired by team members and they started trying to get pregnant during a field trip in Bolivia. When she became pregnant soon, she wondered if the worm infection was effective.

　　The team found that women infected with the most common worm (a type of worm) usually give birth to their first child later, with a relatively long interval between births. However, women infected with another worm, roundworm, seem to have experienced the opposite. The first pregnancy was premature, and the interval between births was very short. It is estimated that women infected with roundworm have two children in their lifetime, and women infected with the worm have three fewer than uninfected women.

　　"What surprised us was the extent of this impact." Blackwell said, "I didn't expect such a big change in the fertility rate of women." Carefully include other possible explanations in the analysis.