Individual characteristics
abortion
CHRONIC DISEASES
Individual characteristics were collected in relation to both parents and the infant. Maternal characteristics included age, body mass index, level of education, occupation, whether the pregnancy was planned, number of previous births, history of abortion, mode of birth, type of anesthesia or anesthesia in case of caesarean section, chronic diseases, use of drugs during pregnancy, use of steroids, the number of possible doses of steroids and the use of iron and complementary drugs used. Paternal characteristics included level of education, occupation, and socio-economic status. The characteristics of the infant included weight, height, head circumference, gestational age at birth based on ultrasound, age upon entry to the study, infant sex assigned at birth, cause of infant hospitalization, and mode of infant feeding. Maternal and paternal information was self-recorded by adult participants. Infant participant data was extracted from medical records.