Reproductive Endocrinology

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated May 14, 2026

Reproductive Endocrinology is the study of hormonal regulation of reproduction, encompassing the hypothalamic-pituitary-gonadal axis and its effects on ovulation, implantation, and pregnancy maintenance. As a conventional subspecialty, Reproductive Endocrinology and Infertility (REI) developed with close ties to assisted reproductive technology, making IVF a central clinical pathway for many fellowship-trained practitioners. Restorative reproductive medicine, in practices such as NaProTechnology and NeoFertility, applies the same endocrine science to a different goal. Hormonal evaluation is timed to cycle phases identified through cycle-timed diagnostics rather than drawn on arbitrary calendar dates, and findings direct restorative treatment rather than bypass procedures. Conditions such as hypothyroidism, hyperprolactinemia, diminished ovarian reserve, and hormonal abnormalities that contribute to infertility or pregnancy loss are identifiable through targeted endocrine workup and are treated at the source.¹² Key hormones in this evaluation include FSH, LH, TSH, and hCG, each interpretable only within the context of the cycle phase at the time of the draw.

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.