Neuroblastoma (NB), an embryonic tumour arising from neural crest cells, ă is the most common malignancy among infants. The aetiology of NB is ă largely unknown. We conducted a pooled analysis to explore whether there ă is an association between NB and preconception and perinatal factors ă using data from two French national population-based case-control ă studies. The mothers of 357 NB cases and 1783 controls younger than 6 ă years, frequency-matched by age and gender, responded to a telephone ă interview that focused on demographic, socioeconomic and perinatal ă characteristics, childhood environment, life-style and maternal ă reproductive history. Unconditional logistic regression was used to ă estimate pooled odds ratios and 95% confidence intervals. After ă controlling for matching variables, study of origin and potential ă confounders, being born either small (OR 1.4 95% CI 1.0-2.0) or large ă (OR 1.5 95% CI 1.1-2.2) for gestational age and, among children younger ă than 18 months, having congenital malformations (OR 3.6 95% CI ă 1.3-8.9), were significantly associated with NB. Inverse associations ă were observed with breastfeeding (OR 0.7 95% CI 0.5-1.0) and maternal ă use of any supplements containing folic acid, vitamins or minerals (OR ă 0.5 95% CI 0.3-0.9) during the preconception period. Our findings ă reinforce the hypothesis that fetal growth anomalies and congenital ă malformations may be associated with an increased risk of NB. Further ă investigations are needed in order to clarify the role of folic acid ă supplementation and breastfeeding, given their potential importance in ă NB prevention.