How your baby develops taste and smell in utero
Read time: 3 minutes
Advances in early life research have revealed that as your unborn baby’s sense of taste and smell develop, they start to form opinions about the foods you eat6. Their taste buds mature as early as 13 weeks, which means they can start developing a taste for food early in the second trimester1. In addition, from the 16th week of your pregnancy onwards, your baby’s sense of smell will be working1,2.
By the end of your pregnancy, your baby will regularly swallow large amounts of amniotic fluid and studies have shown that this could have an impact on your baby’s food preferences later when weaning2.
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 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 weaning2-4.
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 weaning2,4.
Your baby’s sense of smell
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.
- Lecanuet JP, Schaal B. Fetal sensory competencies. Eur J Obstet Gynecol Reprod Biol 1996;68:1-2.
- Ventura AK, Worobey J. Early influences on the development of food preferences. Curr Biol 2013;23(9):R401-8.
- Mennella JA et al. Garlic ingestion by pregnant women alters the odour of amniotic fluid. Chem Senses 1995;20:207-9.
- Mennella JA et al. Prenatal and postnatal flavour learning by human infants. Pediatrics 2001;107:E88-E93.
- Varendi H et al. Attractiveness of amniotic fluid odor: Evidence of prenatal olfactory learning? Acta Paediatr 1996;85:1223-7.
- Schaal B et al. Human foetuses learn odours from their pregnant mother’s diet. Chem Senses 2000;25:729-37.
Questions about feeding and nutrition?
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