Measures of human olfactory perception during pregnancy

Area of Science:

• Neuroscience
• Human Physiology
• Sensory Science

Background:

• Anecdotal evidence suggests pregnancy alters olfactory sensitivity.
• Scientific data on pregnancy's effects on smell perception remains limited and inconclusive.
• Previous studies show pregnancy impacts hedonic (pleasantness) ratings but not odor identification.

Purpose of the Study:

• To investigate olfactory perception across pregnancy and the postpartum period.
• To assess changes in odor identification, intensity, pleasantness, and self-rated sensitivity.
• To clarify the scientific evidence regarding olfactory changes during pregnancy.

Main Methods:

• 100 non-smoking women (pregnant, postpartum, nulliparous controls) were tested.
• The University of Pennsylvania Smell Identification Test (UPSIT) was administered.
• Odor intensity, pleasantness ratings, scratch patterns, and self-rated sensitivity were collected.

Main Results:

• No significant differences in mean UPSIT scores (odor identification) were found between groups.
• During the first trimester, odors were rated as more intense and less pleasant.
• Pregnant women reported altered pleasantness and scratched odor strips less frequently.
• Self-rated olfactory sensitivity was higher in pregnant women but not correlated with objective measures.

Conclusions:

• Pregnancy does not significantly alter objective odor identification abilities.
• Subjective reports of altered smell perception during pregnancy are common but may not reflect objective changes.
• The effect of pregnancy on olfaction appears to be small and inconsistent across individuals and measures.