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Polycystic Ovary Syndrome pp 107–121Cite as

Pubertal Precursors of the Polycystic Ovarian Syndrome

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Part of the book series: Contemporary Endocrinology ((COE))

Summary

Polycystic ovarian syndrome (PCOS) is a disorder characterized by ovulatory dysfunction and hyperandrogenemia. In the majority of women with PCOS, luteinizing hormone (LH) [gonadotropin-releasing hormone (GnRH)] pulse frequency is persistently rapid, which favors synthesis of LH and elevated plasma LH that in turn stimulates increased androgen production. Rapid GnRH frequencies are not optimal for FSH synthesis and secretion, contributing to impaired follicular maturation. In normal women, luteal phase concentrations of progesterone markedly slow GnRH pulse frequency (to one pulse every 3–4 h), but in anovulatory women with PCOS, this does not occur. In part, this reflects the low levels of circulating progesterone, but studies have also demonstrated reduced hypothalamic sensitivity to progesterone inhibition of GnRH secretion. The reduced sensitivity to progesterone appears to be the result of elevated androgens, as sensitivity is restored following treatment with the anti-androgen, flutamide. In the etiology of the disorder PCOS, ovulatory and hormonal abnormalities are commonly observed during puberty, with plasma measurements revealing hyperandrogenemia. In some girls, impaired hypothalamic progesterone sensitivity is present, similar to that in adult women, though not all hyperandrogenemic adolescents are affected. We propose that the pre- and early-pubertal hyperandrogenemia interferes with normal ovarian hypothalamic regulation of GnRH pulse frequency, leading to a persistently rapid frequency of GnRH pulse secretion. This in turn favors LH synthesis and secretion, further stimulating ovarian testosterone secretion and impairing normal regulation of ovulatory function.

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Authors
  1. John C. Marshall MD PHD
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  2. Christopher R. McCartney MD
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  3. Susan K. Blank MD
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  4. Quirine Lamberts Okonkwo MD
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Editor information

Editors and Affiliations

  1. Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University, Chicago, IL

    Andrea Dunaif MD

  2. Department of Reproductive Medicine, University of California, San Diego School of Medicine, La Jolla, CA

    R. Jeffrey Chang MD

  3. Institute of Reproductive and Developmental Biology, Imperial College London, London, UK

    Stephen Franks MD, FMEDSCI

  4. Department of Ob/Gyn, Penn State College of Medicine, Hershey, PA

    Richard S. Legro MD

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Marshall, J.C., McCartney, C.R., Blank, S.K., Okonkwo, Q.L. (2008). Pubertal Precursors of the Polycystic Ovarian Syndrome. In: Dunaif, A., Chang, R.J., Franks, S., Legro, R.S. (eds) Polycystic Ovary Syndrome. Contemporary Endocrinology. Humana Press. https://doi.org/10.1007/978-1-59745-108-6_7

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