The Possibility of Morning Sickness from Olfactory Hypersensitivity during Pregnancy

Background and ObjectivesZZNausea and vomiting in early pregnancy are well-known phenomena. It has been suggested that the mechanism that triggers nausea and vomiting in pregnancy may be related to olfactory changes. We planned to investigate olfactory function changes and the relationship between olfaction changes and nausea and vomiting in early pregnancy. Subjects and MethodsZZTwo groups of participants with the total of 75 women (35 pregnant women; 40 non-pregnant women) were analyzed prospectively. Objective olfactory function was tested using Korean Version of Sniffin’ Sticks-II test (KVSS-II test). In addition, pregnant subjects were investigated using the questionnaire to evaluate the severity of nausea and vomiting, and whether the changes were due to olfactory sensitivity. ResultsZZSubjective olfactory sensitivity was increased in pregnant subjects. However, there was no significant difference in the objective olfactory function between the two groups. ConclusionZZBased on this study, we concluded that pregnancy is accompanied by changes in subjective olfactory sensitivity and higher subjective olfactory discomfort. But these findings do not support the hypothesis that nausea and vomiting is dependent of the changes in the objective olfactory function during early pregnancy. Korean J Otorhinolaryngol-Head Neck Surg 2011;54:473-6 Key WordsZZOlfactory function ㆍPregnancy ㆍMorning sickness nausea ㆍVomiting.