Research just published in the journal Science (Helminth infection, fecundity, and age of first pregnancy in women) studied the effects of parasites from the family Helminth on human fertility, specifically in Tsimane women in Bolivia, who experience a 70% infection rate of these these organisms. The results of the nine year study of 986 women found that infection by the roundworm Ascaris lumbricoides appears to increase fertility, apparently by modifying the host’s immune system; conversely, those infected with hookworm exhibit delayed first pregnancy and extended interbirth intervals.

btm said:

Research just published in the journal Science (Helminth infection, fecundity, and age of first pregnancy in women) studied the effects of parasites from the family Helminth on human fertility, specifically in Tsimane women in Bolivia, who experience a 70% infection rate of these these organisms. The results of the nine year study of 986 women found that infection by the roundworm Ascaris lumbricoides appears to increase fertility, apparently by modifying the host’s immune system; conversely, those infected with hookworm exhibit delayed first pregnancy and extended interbirth intervals.

I’ve noticed that infections can have an effect on male libido, a resulting mild high temperature up 1°C increases libido. a higher temperature increase of more than 2°C decreases libido. I don’t know if this is also true for women. If so, then this provides a mechanism linking Helminth infections to fertility.