Hookworms are parasitic worms that live in the intestine and can cause a lower than normal number of red blood cells.
In a systematic search of medical databases, reference lists and unpublished data, the scientists were able to compare levels of hemoglobin -- the oxygen-carrying part of red blood cells -- according to the intensity of hookworm infection among the women studied. They found increasing intensity of infection was associated with lower levels of hemoglobin.
"Most of the studies showed hookworm was associated with maternal anemia, and that there are clear benefits of de-worming for both maternal and child health" said Simon Brooker of the London School of Hygiene & Tropical Medicine. "In many developing countries it is policy that pregnant women receive de-worming treatment, but in practice coverage rates are often unacceptably low."
The study by Brooker, Peter Hotez of George Washington University and Donald Bundy of The World Bank, appears in the journal PLoS Neglected Tropical Diseases.