How your baby develops taste and smell in utero

Even before birth, babies show a preference for sweet tastes – but why? The answer may lie in the complex mix of nutrients, amino acids and glucose that make up amniotic fluid.

Naturally slightly sweet in flavour, studies have shown that if even sweeter flavours are injected into the fluid, a baby will start to swallow more. But they will stop swallowing amniotic fluid if bitter flavours are introduced². This early preference for sweeter tastes continues when your newborn is fed breast milk, as it also has a sweet taste.

But amniotic fluid isn't just sweet. Research has shown that strong flavours from the foods you eat are also present. Incredibly, repeated exposure to these flavours can influence a baby’s enjoyment of them once they start weaning^2-4.

In one study, mums-to-be were asked to drink a lot of carrot juice in their third trimester. When their babies began weaning months later, they enjoyed carrot-flavoured cereal more than the control group whose mums hadn’t had the juice⁴.

This development of food preferences doesn’t just start in the womb, it also carries on throughout breastfeeding, as breast milk also contains flavours from the foods you eat. Taste imprinting is thought to explain the continuation of cultural preferences for foods flavoured with particular herbs or spices. Repeated exposure to these flavours, via amniotic fluid and later through breast milk, can influence a baby’s enjoyment of them once they start weaning^2,4.

Your baby’s sense of smell is thought to develop prior to birth as newborn babies know and prefer their mother’s smell almost immediately.  In one study, when offered the choice between feeding from a breast that had amniotic fluid on it and one that hadn’t, most babies chose the one that smelt of amniotic fluid, suggesting it triggers memory⁵.

But babies don’t just have a preference for the scent of their mother. They prefer the smell of the foods you eat most of in pregnancy, too6. Further research has shown that babies whose mums had eaten a lot of star anise during pregnancy enjoyed the smell once they were born while those that hadn’t had prior exposure, didn’t⁶. This finding suggests you have the power to influence your baby’s likes and dislikes through your own dietary choices, even at this early stage.

Through these advancements in early life science, it’s clear that a healthy, balanced pregnancy diet provides you and your baby with more than just essential nutrients and that it can impact your baby’s experience with different foods during weaning.