Design: Data are from the baseline survey of the longitudinal cohort study IDEFICS in eight European countries.
Subjects: A total of 420 parents from eight countries (43–61 per country) were asked to complete the parental questionnaire (PQ) twice at least 1 month apart.
Measurements: The PQ assesses prenatal (maternal weight gain), perinatal (child's birth weight and length, Caesarean (C)-section, week of delivery) and early postnatal factors (exclusive breastfeeding, breastfeeding, introduction of solid food). Intra-class correlation coefficients (ICCs) were calculated to compare maternal reports on prenatal, perinatal and early postnatal factors between the first and second PQ.
Results: In total, 249 data sets were considered for the analyses. Overall, maternal reports for prenatal and perinatal factors showed higher repeatability (ICC=0.81–1.00, Pless than or equal to0.05 for all) than those for early infant nutrition (ICC=0.33–0.88, Pless than or equal to0.05 for all). Perfect agreement was found for parental reports on C-section (ICCall=1.00, Pless than or equal to0.05). There was stronger agreement for duration of breastfeeding (ICC=0.71, Pless than or equal to0.05) compared with exclusive breastfeeding (ICC=0.33, Pless than or equal to0.05). Maternal reports showed moderate correlation for the introduction of several types of food (cereals ICC=0.64, Pless than or equal to0.05; fruits ICC=0.70, Pless than or equal to0.05; meat ICC=0.83, Pless than or equal to0.05; vegetables ICC=0.75, Pless than or equal to0.05), and high correlation (ICC=0.88, Pless than or equal to0.05) for cow's milk.
Conclusion: Maternal reports on pregnancy and birth were highly reproducible, but parental recall of early infant nutrition was weaker and should be interpreted more cautiously.