Brain age is stable across the menstrual cycle: results from a high-density sampling study

Motivation: Ovarian hormones are considered to have a neuroprotective effect on brain morphology, but this effect has not been adequately studied across acute changes in the menstrual cycle. Goal(s): This study aimed to investigate brain age predictions across phases of the menstrual cycle. Approach: High-density sampling methodology (43 MRI scans across 100 days) with one female participant was used to fully characterise the menstrual cycle. The ENIGMA brain age prediction model was used to generate brain age with structural metrics. Results: Despite notable variation, no significant change across the menstrual cycle was found in brain-PAD. Impact: Menstrual cycle phases may not provide a sufficient representation of endocrine influences on neuroanatomy. Therefore, future research should investigate the potential effect of measured ovarian hormone levels on brain morphology, utilizing an age prediction framework.