Role of maternal alcohol intake during pregnancy in early-life child neurodevelopment: results of the Italian PHIME cohort

Introduction Prenatal alcohol exposure (PAE) is a well-established risk factor for adverse neurodevelopmental outcomes, particularly at high levels of consumption. The impact of low-to-moderate PAE remains unclear, with mixed results reported. This study investigates the effects of low-level PAE on neurodevelopmental outcomes at 18 months in Italian mother-child pairs enrolled in the Italian Northern Adriatic Cohort II, a part of the ‘Public health impact of long-term, low-level, mixed element exposure in susceptible population strata’ project PHIME. Methods The study population consisted of 632 children, and their mothers, who were tested with the Bayley Scales of Infant and Toddler Development third edition (BSID-III) at 18 months of age. PAE, socio-demographic and lifestyle information was collected through questionnaires at different phases of follow-up. We analysed 605 children born at term (≥37 weeks) with BSID-III data and maternal pregnancy alcohol intake estimates. Multiple linear regression assessed associations between each BSID-III composite score (cognitive, motor, language) and PAE. Results Mothers’ alcohol consumption was very low. The median (25th percentile to 75th percentile) of the weekly alcohol intake of the 605 mothers was 0.3 (0–1.4) drinks and of the children’s cognitive, language and motor composite score were 105 (100–110), 97 (91–103) and 100 (97–107), respectively. No significant association was found between maternal alcohol intake and BSID-III cognitive nor language scores. Only a suggestive, non-consistent, inverse association was found between PAE and motor neurodevelopment. Maternal IQ and promotion of child autonomy were directly associated with all neurodevelopmental outcomes. Conclusion Low levels of PAE were not associated with neurodevelopmental impairment at 18 months, except for possible motor impairment at higher exposures: our findings highlight the predominant influence of maternal IQ and the home environment. Further research, including a broader range of alcohol exposure, is needed to better define potential safety thresholds of PAE on early-life neurodevelopment.