Abstract

Circadian rhythm is a 24-hour cycle, an internal biological cycle controlled by the SCN in the hypothalamus. Similarly, Infradian rhythm is longer than 24 hours (e.g., menstrual cycle, monthly or seasonal changes). These rhythms play a crucial role in the postpartum period for women. Carlson et al. (2025) show that women after delivery may physically and mentally regress to the extreme physiological, hormonal, and emotional demands of childbirth and postpartum recovery, resulting in a more vulnerable or exhausted state that resembles a regression of many years in terms of energy levels, hormonal balance, and cognitive resilience due to multiple neurological changes. This review highlights the significance of functional neuroanatomy concerning circadian and infradian rhythms among postpartum women. This systematic review aims to help understand and evaluate this under-researched topic in neuroscience. It reviews up to 18 recent studies to analyze functionality and suggest directions for future research in this field. Key findings also show that disrupted sleep can cause mood swings and severe depression in early motherhood, indicating that disrupted circadian rhythms can be linked to infradian rhythms.