Search for Olfactory Cells Within the Fetal Ethmoid Epithelium
The recent rhinological functional approach known as "Evo-Devo" leads us to consider the nose not as a single organ, but as the construction of a specifically olfactory organ within which functional respiratory structures have developed over the course of species evolution in the same way they develop during human embryogenesis.

In adult humans, the olfactory structures are limited to two narrow regions situated at the upper part of the nasal passages known as olfactory clefts. Nevertheless, phylogenetic evidence indicates that these olfactory clefts are vestiges of an olfactory organ that once occupied the entire ethmoid bone in the front of the skull base.

The hypothesis of this study posits that, during the embryological development of the ethmoid bone, it would initially be covered with olfactory mucosa, which would gradually diminish as the lateral masses of the ethmoid formed, eventually persisting exclusively within the olfactory clefts of the ethmoid by the conclusion of the first trimester (end of organogenesis). Besides their fundamental interest, the results of this study could help understand the still unknown pathogenesis of nasal polyposis, a chronic anosmic disease with a prevalence of 2 to 4% in the French and European population.

This study requires a series of ethmoidal samples from human fetuses at various ages between 7 and 15 weeks of gestational age. Specific immunohistological labeling techniques under standard optical microscopy will be used to search for and quantify olfactory nerve cells within the fetal ethmoidal mucosa.
- EligibilityCriteria: Inclusion Criteria:  Fetus aged at least 7 weeks of gestation up to 14 weeks + 6 days. Fetus resulting from an in-hospital procedure of voluntary termination of pregnancy, either medicinal or surgical. Fetus whose mother is of legal age and legally responsible. Fetus whose mother has been provided with fair and complete information about the research conducted and has given informed, voluntary, and written consent for the use of fetal products from the voluntary termination of pregnancy procedure she is undergoing. Fetus whose mother has not objected to the utilization of data derived from the research.  Exclusion Criteria:  Fetus macroscopically exhibiting a craniofacial malformation - Gender: All - MinimumAge: 7 Weeks - MaximumAge: 15 Weeks - StdAgeList: Child - StudyPopulation: Fetus aged 7 to 14+6 weeks of gestational age resulting from an in-hospital voluntary termination of pregnancy procedure - SamplingMethod: Non-Probability Sample