The timing of introducing complementary feeding affects nutritional status and children's health. The aim of this study was to determine sociodemographic and birth-related factors associated with the age of introducing complementary foods. This cross-sectional study investigated parents (n = 5815) of children aged 12-36 months from Poland (n = 4065) and Austria (n = 1750) using a single online questionnaire. During the study, detailed data about sociodemographic characteristics, variables related to pregnancy, and early feeding practices were collected. Univariate and multivariate logistic regression models were used to investigate factors associated with the introduction of complementary feeding before 4 completed months, between 4 and 6 months, and after 6 completed months separately for both countries. Complementary foods were introduced before 4 months in 3.0% of infants (2.4% in Poland and 4.3% in Austria), between 4 and 6 months in 65.0% (60.5% in Poland and 75.3% in Austria), and after 6 completed months in 32.1% of infants (37.1% in Poland and 20.4% in Austria). The factors related to earlier introduction of complementary feeding were lower maternal age (in Austria 25-29 years: aOR 2.21 (95% CI 1.06-4.65)) and education level (in Poland and Austria primary and vocational: aOR 14.49 (95% CI 3.73-56.35), aOR 2.13 (95% CI 1.10-4.11), respectively), preterm birth (in Poland and Austria: aOR 10.21 (95% CI 5.73-18.20); aOR 4.45 (95% CI 2.42-8.18), respectively), never breastfeeding (Poland: aOR 2.73 (95% CI 1.29 - 5.76)) and receiving an infant formula after hospital discharge (in both countries: aOR 3.73 (95% CI 2.06-6.75); aOR 3.65 (95% CI 1.87-7.12), respectively). These factors should be taken into account by health professionals in identifying mothers who are least likely to follow nutritional recommendations.
Keywords: breastfeeding; infant feeding; introduction of complementary feeding; introduction to solids; preterm infants; risk factors; weaning.