The study authors note that it is important for expectant mothers to use antibiotics appropriately and when necessary, as well as monitor their child after birth.

Childhood allergic diseases have increased, and although they are common chronic inflammatory conditions, these allergies often coexist with other comorbidities (eg, obesity, sleep disorders) that reduce quality of life. Infancy is a critical period in which the microbiome develops, as it affects the development of the immune system.
The microbiome can be influenced by different factors (eg, mode of delivery, breast feeding, exposure to antibiotics). Further, the use of antibiotics during pregnancy has not been extensively evaluated. A recent study published in The Journal of Allergy and Clinical Immunology: Global evaluated the association of maternal exposure to antibiotics during pregnancy with childhood allergic disease up 3 years of age.

A total of 78,678 expectant mothers and their offspring, aged 0 to 3 years, were enrolled in the study. Exclusion criteria consisted of birth by caesarean section, extremely high (≥4000 g) or low (<1000 g) birth weight, and the absence of information regarding antibiotic use. The study’s outcome variables included preschool asthma, wheezing, food allergy (FA), atopic dermatitis (AD), eczema, allergic rhinoconjuctivitis, and any allergic disease, with the prevalence of allergic diseases assessed on the basis of caregiver-reported physician’s diagnosis from the questionnaires at each age.

Prenatal antibiotic exposure was defined as the use of any antimicrobial agent during pregnancy. Information on prenatal antibiotic exposure was collected through an interview questionnaire answered by the mothers at enrollment (eg, “Did you take any antibiotics between the confirmation of pregnancy and gestational age of 12 weeks?” and “Did you take any antibiotics from after gestational age of 12 weeks until now?”) and again during mid-to-late pregnancy, and the review of medical record transcripts developed after delivery. Further, the timing of antibiotic exposure was divided into the first trimester (T1) and second/third trimester (T2/T3).

Results indicate that maternal antibiotic exposure is associated with an increased risk of respiratory allergies in offspring, particularly preschool asthma, allergic rhinoconjunctivitis, wheezing, and any allergic disease up to age 3 years. In addition, the results show that maternal antibiotic use did not contribute to the risk of developing FA, AD, and eczema. Of the total 78,678 mothers included in the study, 22,433 (28.5%) had used antibiotics during pregnancy, with preschool asthma (unexposed: 10.8%; exposed: 12.5%), wheezing (unexposed: 38.2%; exposed: 41.6%), FA (unexposed: 12.8%; exposed: 13.2%), AD (unexposed: 11.3%; exposed: 11.7%), eczema (unexposed: 28.6%; exposed: 28.9%), allergic rhinoconjuctivitis (unexposed: 8.0%; exposed: 9.1%), and any allergic disease up to 3 years (unexposed: 59.6%; exposed: 62.5%) being prevalent. According to the study authors, these findings were not influenced by the timing of antibiotic exposure, gender of the infant, or maternal history of allergies, with the exception of childhood allergic rhinoconjunctivitis risk in the offspring of mothers without a history of allergies.

Reference
Okoshi, K, Sakurai, K, Yamamoto, M. Maternal antibiotic exposure and childhood allergies: The Japan Environment and Children’s Study. JACI: Global. 2023;2(4). doi:10.1016/j.jacig.2023.100137