Sense of taste

Your unborn baby can’t hear the world around them until you’re at least 24 weeks pregnant as the cochlea, the sense organ translating sound into nerve impulses, hasn’t connected to their brain until then. However, their sense of taste develops much earlier. In fact their taste buds mature as early as 13 weeks, which means they can start developing a taste for food early in the second trimester.

In addition, from the 16th week of your pregnancy onwards, your baby’s sense of smell will be working and they will start to inhale amniotic fluid. By the end of your pregnancy, they’ll regularly swallow large amounts of amniotic fluid and studies have shown that the ability to savour its flavour could have an impact on your baby’s food preferences.

Amniotic fluid and its unique properties

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 if bitter flavours are introduced. This early preference continues when your newborn is fed breast milk, which 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. In one study, mums-to-be were asked to drink lots 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 juice. Another study showed that babies whose mums had eaten lots of garlic were more likely to happily tuck into garlicky foods.

You may have heard of ‘taste imprinting’, but let’s explore how it works and what it means beyond birth. 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.

Sense of smell

The aroma of food can summon vivid memories: warm apple pie may be reminiscent of tea at Grandma’s, while popcorn might remind you of a scary film. Again this is thought to start prior to birth. Newborns know and prefer their mother’s smell almost immediately and, in one study, when offered the choice between feeding from a breast that had amniotic fluid on it and one that hadn’t, most chose the one that smelt of amniotic fluid, suggesting it triggers memory. 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 too. Further research has shown that babies whose mums had eaten lots of star anise during pregnancy enjoyed the smell once they were born while those that hadn’t had prior exposure didn’t. This fascinating finding suggests you have the power to influence your baby’s likes and dislikes through your own dietary choices, even at this early stage.

A healthy diet

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. This is key to their enjoyment and experience of different foods at weaning, which is definitely food for thought.