Children's Immune System Affected.

• Position: MALARIA PREGNANCIES

Mothers infected with malaria during pregnancy can pass more of their own cells to their baby and change the infant's risk of later infection, shows a study in the Journal of Infectious Diseases, which suggests that a mother's cells directly could act as part of her child's immune system, even after birth.

The placenta blocks some infectious agents, but easily passes oxygen and nutrients to the baby. It also allows a unique exchange of cells between mother and child, known as "microchimerism." The research team looked at how malaria can alter the mother-child cell sharing that occurs during pregnancy.

Most babies carry a very small number of foreign cells acquired from their mothers, on the order of a few maternal cells in every 100,000, but the researchers found that babies bom to Tanzanian mothers infected with malaria during pregnancy, and whose infections had traveled to their placenta, had evidence for far more maternal cells on-board at the time of their births--on average about one percent, with a few cases even higher than 10%.

The level of increase of mother's cells present in baby's blood was a surprise to the researchers, who hypothesize that the infection led to alterations in placental proteins that control cell trafficking, which allow more maternal...