We thank Carpay et al for reading our work and for their comment. As they note, we do consider group B Streptococcus (GBS) IAP different from most other forms of early-life antibiotics and agree that duration of total therapy is also a part of that difference. We studied a cohort of 14 046 children from birth to 5 years and did not find an association between GBS IAP and allergic disorders. However, to answer the question, many early-life antibiotics have adverse association, and so, if given for long enough, would GBS IAP have an association as well? There is a 2-part answer. First, in terms of clinical relevance, GBS IAP is rarely administered for >24 hours. In our cohort, 3% of women administered GBS IAP received it for >24 hours. As our goal was to determine adverse associations with GBS IAP as recommended in routine practice, we did not pursue further investigation into duration >24 hours because this was a rare occurrence, unlikely to have a large population effect. Second, most observational studies investigating early-life antibiotics do not separate the indication of antibiotic administration from antibiotic administration itself. A neonate administered 5 days of antibiotics in the first week of life surely has some symptomatology of illness or markers of inflammation. How does one adjust away that indication? GBS IAP is not administered for symptomatology but for colonization status, something we could adjust for because the overlap between the 2 variables was incomplete. Hence, by design, we focused on an exposure that we thought reduced this confounding by indication. Additionally, as noted by the authors, the association of neonatal antibiotics and multiple adverse outcomes have been reported by others. We do not doubt that there is a biological plausibility for an independent association of early-life antibiotics and immune alteration and duration of therapy being an important determinant in that relationship. However, our article was focused on a specific national policy, and we limited ourselves to just that exposure. Your suggestion is appreciated, and we will keep it in mind for our future projects.
CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.