2.3 Potential confounders or covariates
We considered the following covariates for potential association with
exposure and outcome based on previous studies.2,12Maternal factors included maternal age, urbanization, insurance
property, mode of delivery, type of pregnancy, acetaminophen use during
pregnancy, maternal atopic disorders, gestational infections, and
maternal comorbidities, including hypertension, diabetes mellitus,
hyperlipidemia, malignancy, urinary tract infection, maternal asthma,
rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome,
endometriosis, gestational diabetes, and preeclampsia. Infant factors
included birth year, child’s sex, length of gestation, birth weight, and
APGAR score at birth. In addition, postnatal antibiotic and
acetaminophen exposure in the first year of life were also selected as
variables based on previous reports.