Human Foetuses Learn Odours from their Pregnant Mother's Diet

TLDR

Olfactory responsiveness was evaluated in 24 newborns whose mothers either consumed anise during pregnancy or not, with infants tested for attraction or aversion to anise and a control odor immediately after birth and on day 4. Infants of anise‑consuming mothers consistently preferred anise odor, whereas infants of non‑consuming mothers showed aversion or neutrality, demonstrating that maternal diet shapes neonatal hedonic olfactory responses and suggesting implications for early mother‑to‑infant chemosensory transmission.

Abstract

Olfactory responsiveness was assessed in 24 neonates born to mothers who had or had not consumed anise flavour during pregnancy. Both groups of infants were followed-up for behavioural markers of attraction and aversion when exposed to anise odour and a control odour immediately after birth and on day 4. Infants born to anise-consuming mothers evinced a stable preference for anise odour over this period, whereas those born to anise non-consuming mothers displayed aversion or neutral responses. This study provides the first clear evidence that through their diet human mothers influence the hedonic polarity of their neonates’ initial olfactory responses. The findings have potential implications for the early mother-to-infant transmission of chemosensory information relative to food and addictive products.