Follicular Circadian Reproductive Rhythms: A Mathematical Model

The female reproductive endocrine system primarily consists of gonadotropin releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (estradiol or E2), and progesterone (P4). Pulses of GnRH prompt the production of LH and FSH, which in turn stimulates estradiol and progesterone growth. While a monthly model of these hormones is widely known, our bodies have a circadian rhythm, and certain hormones fluctuate on a daily basis. Studies suggest that these hormones more closely follow a circadian rhythm during the follicular phase. Thus, this research paper will map the fluctuation of the hormones most involved in the menstrual cycle on a minute-by-minute scale, under the influence of melatonin, to demonstrate circadian rhythm during the follicular phase.