BACKGROUND AND OBJECTIVES: Partially hydrolysed formulas (pHF) are recommended in non-breastfed infants with familial history of allergy to prevent allergy development. However, recent meta-analysis does not provide strong support for their protective effect. The present work assesses the links between 2-month infant formula use and the incidence of eczema, respiratory symptoms or food allergies (FA) up to 2 years of age. METHODS: The nationwide ELFE birth cohort is a population-based study from mainland France. Infant feeding (breast milk only, partially-hydrolysed formula with (pHF-HA) or without a hypoallergenic label (pHF-non-HA) and non-hydrolysed formula (nHF)) was reported at 2 months. Eczema, FA and respiratory symptoms such as wheezing and asthma were reported at 2 months, 1 year and 2 years. Infant with prior FA at 2 months were excluded from analyses. RESULTS: Among 11,720 infants, those who received only breast milk at 2 months were at lower risk of eczema at 1 year than those who received nHF (OR[95% CI]=0.78[0.65-0.94] in non-at-risk infants; 0.86[0.75-0.98] in at-risk infants). The use of pHF-HA, compared with nHF, at 2 months was related to higher risk of wheezing at 1 year in at-risk infants (1.68[1.24-2.28]), and higher risk of FA at 2 years both in non-at-risk infants (3.78[1.52-9.41]) and in at-risk infants (2.31[1.36-3.94]). CONCLUSIONS: In this nationwide study, pHF-HA use was not associated with a lower risk of any of the studied outcomes. Quite the reverse, it was associated with a higher risk of wheezing and FA. This should be confirmed in further studies. This article is protected by copyright. All rights reserved.< Réduire