If you’re pregnant, and suffer from asthma, you might want to avoid taking antibiotics if you can manage it. New research suggests that asthmatic women who take antibiotics during pregnancy are more likely to have children who will also be diagnosed with asthma. In fact, children whose mothers took antibiotics during pregnancy were twice as likely to be diagnosed with the lung disorder by 3 years of age than children of women who did not take antibiotics during their pregnancies.

There’s already significant concern that antibiotic overuse is encouraging the development of drug-resistant “superbugs,” which medical science may be powerless to defeat. Concerns about the possible role of antibiotic use in encouraging obesity are also growing. In the present study, scientists wondered if there is a link between antibiotic use and asthma among children who are already at risk for the disease, because they have a parent who suffers from asthma, allergies, or eczema. 

Investigators note that the prevalence of asthma has doubled in the developed world over the last three decades. In a press release, study author Brittany Lapin, MPH, said, “The message to pregnant women is to avoid antibiotics to the extent that they can, and possibly avoid asthma development in their children.”

Of course, doctors are not recommending that pregnant women take unnecessary risks with their health. “We wouldn't recommend not giving antibiotics to a pregnant woman,” said study co-author, Dennis Ownby, MD, “but we recommend caution when symptoms are not clearly caused by a bacterial infection. Pregnant women with asthma should work with their allergist to create a healthy outcome for themselves and their children.”

Previous research has suggested that other factors associated with a baby’s increased asthma risk include having a mother who was overweight during pregnancy, delivery by caesarean section, and having a mother who was exposed to air pollution during the second trimester of pregnancy. 

Brittany Lapin, Julie Piorkowski, Dennis Ownby, Sally Freels, Noel Chavez, Eva Hernandez, Cynthia Wagner-Cassanova, Darlene Pelzel, Carmen Vergara, Victoria Persky. Relationship between prenatal antibiotic use and asthma in at-risk children. Annals of Allergy, Asthma & Immunology, 2015; 114 (3): 203 DOI: 10.1016/j.anai.2014.11.014

S. P. Patel, A. Rodriguez, M. P. Little, P. Elliott, J. Pekkanen, A.-L. Hartikainen, A. Pouta, J. Laitinen, T. Harju, D. Canoy, M.-R. Jarvelin. Associations between pre-pregnancy obesity and asthma symptoms in adolescents. Journal of Epidemiology & Community Health, 2011; DOI: 10.1136/jech.2011.133777

American Thoracic Society (ATS). "Exposure to air pollution during second trimester of pregnancy may be associated with increased asthma risk in children." ScienceDaily. ScienceDaily, 19 May 2014.

M. C. Magnus, S. E. Haberg, H. Stigum, P. Nafstad, S. J. London, S. Vangen, W. Nystad. Delivery by Cesarean Section and Early Childhood Respiratory Symptoms and Disorders: The Norwegian Mother and Child Cohort Study. American Journal of Epidemiology, 2011; 174 (11): 1275 DOI: 10.1093/aje/kwr242