Helminth infection, fecundity, and age of first pregnancy in human females

• Authors: Aaron D. Blackwell, University of California Santa Barbara; Marilyne Tamayo, University of Missouri; Bret Beheim, University of New Mexico; Benjamin C. Trumble, University of California Santa Barbara; Jonathan Stieglitz, Tsimane Health and Life History Project; Paul L. Hooper, Emory University; Melanie Martin, University of California Santa Barbara; Hillard Kaplan, University of New Mexico; Michael Gurven, University of California Santa Barbara
• Journal Title: Science
• Volume: Volume 350, Number 6263
• Publisher: American Association for the Advancement of Science | 2015-11-20, Pages 970-972
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1126/science.aac7902
• Subjects: Anthropology, Medical and Forensic; Anthropology, Physical
• Keywords: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; REGULATORY T-CELLS; PLASMODIUM-FALCIPARUM; SICKNESS BEHAVIOR; IMMUNE-RESPONSES; POPULATION; IMMUNOLOGY; MECHANISMS; STRATEGY; SIZE

Abstract

Infection with intestinal helminths results in immunological changes that influence co-infections, and might influence fecundity by inducing immunological states affecting conception and pregnancy.We investigated associations between intestinal helminths and fertility in women, using 9 years of longitudinal data from 986 Bolivian forager-horticulturalists, experiencing natural fertility and 70% helminth prevalence.We found that different species of helminth are associated with contrasting effects on fecundity. Infection with roundworm (Ascaris lumbricoides) is associated with earlier first births and shortened interbirth intervals, whereas infection with hookworm is associated with delayed first pregnancy and extended interbirth intervals. Thus, helminths may have important effects on human fertility that reflect physiological and immunological consequences of infection.