Antibiotic Use By Mother During Pregnancy Associated With Asthma In Child

September 13, 2002

(American Thoracic Society) -- In a study of 24,690 British children, researchers found that exposure to antibiotics in the mother's womb was associated, in a dose-related manner, with an increased risk of asthma in the child, according to an article in the second issue for September 2002 of the American Thoracic Society's peer-reviewed journal.

Writing in the American Journal of Respiratory and Critical Care Medicine, Tricia M. McKeever, M.S.C., of the Division of Respiratory Medicine, University of Nottingham, Nottingham, United Kingdom, along with three associates, found that exposure to antibiotics and to infection in utero are potentially important risk factors in the development of allergic disease. They examined antibiotic use and the development of various infections in the mothers during pregnancy; the problems included viral and bacterial infections such as those in the gastrointestinal and respiratory tracts. They also looked at conjunctivitis, otitis media, and candida. The most common infections involved the respiratory tract and candida (a yeastlike fungus that infects the vagina). Each were diagnosed in 14 percent of the mothers. Approximately one-third of the women were prescribed one or more courses of antibiotics during pregnancy.

"Their exposure was associated with an increased incidence of asthma, eczema, and hay fever in the children," said Ms. McKeever.

Slightly over 20 percent (5,091 children) were diagnosed with asthma or wheeze; just over 31 percent (7,758 children) were diagnosed with eczema.

All study data were derived from the West Midlands General Practice Research Database, drawn from computerized records of routine clinical care.

Maternal depression during the perinatal period was also associated with an increased risk of children being diagnosed with all three allergic diseases, particularly asthma.

Complications of pregnancy were associated with an increased risk of asthma, but not of either eczema or hay fever.

"Antibiotics can cross the placenta and enter the fetal circulation," said Ms. McKeever. "We found a dose-response relationship between antibiotics given during pregnancy and the child's risk of developing an allergic disease. To our knowledge, this is the first time that this association has been reported."

In this study, the investigators found no evidence that previous pregnancies terminated through either a therapeutic or spontaneous abortion reduced the risk of allergic disease in subsequent children.