 Hormonal factors are capable of altering the mucosal barrier . In one study , a small group of females with apthous stomatitis had fewer occurrences of aphthous ulcers during the luteal phase of the menstrual cycle or with use of the contraceptive pill . This phase is associated with a fall in progestogen levels , mucosal proliferation and keratinization . This subgroup often experiences remission during pregnancy . However , other studies report no correlation between aphthous stomatitis and menstrual period , pregnancy or menopause . 
