An investigation into the effects of prenatal flavour exposure through maternal diet on fetal and infant behaviours

Abstract

The research presented in this thesis is an examination of the effects of prenatal flavour exposure on fetal and infant behaviours. Throughout pregnancy, a fetus is exposed to a range of flavours in the amniotic fluid which contains maternal dietary aromas. There is a body of research investigating the effects of prenatal flavour exposure on infant behaviours, however, direct investigation of fetal reactions has to date been lacking. To address this, Chapter 3 examined the fetal facial reactions, via 4D ultrasound scans, to prenatally exposed flavours, namely kale and carrot. The findings indicate the first direct evidence of fetal facial reactions to flavours in the amniotic fluid. Chapter 4 is a systematic review and meta-analysis that indicated that this prenatal flavour experience provides continuous chemosensory information from prenatal to the first year of postnatal life. Chapter 5 indicated that neonates at around one month of age “prefer” the odour of flavours they experienced in the last three weeks of pregnancy. Additionally, a longitudinal analysis that was reported in Chapter 5 shows that fetal reactions to flavours can be modified by repeated exposure in utero, resulting in increased preferences for the exposed flavour irrespective of the type of flavour. This PhD thesis makes an important and novel contribution to the research literature by providing a window into the chemosensory world of the human fetus and showing a potential way to shape postnatal food preferences.