A new model for ovarian follicular development during the human menstrual cycle

Baerwald, Angela R; Adams, Gregg P; Pierson, Roger A

doi:10.1016/S0015-0282(03)00544-2

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Volume 80, Issue 1 , Pages 116-122, July 2003

A new model for ovarian follicular development during the human menstrual cycle☆

Portions of these data were presented at the 46th Annual Meeting of the Canadian Fertility and Andrology Society, St. John’s, Newfoundland, Canada, September 15, 2000 and the 11th World Congress on Human Reproduction, Montreal, Quebec, Canada, June 4, 2002.

Angela R Baerwald, B.Sc. Hon.
- Women’s Health Imaging Research Laboratory, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Reprint requests: Roger A. Pierson, M.S., Ph.D., Department of Obstetrics, Gynecology and Reproductive Sciences, University of Saskatchewan, Room 4519, Royal University Hospital, Saskatoon, Saskatchewan, Canada S7N 0W8 (FAX: 306-966-2212).
Gregg P Adams, D.V.M., M.S., Ph.D.
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
Roger A Pierson, M.S., Ph.D.
- Women’s Health Imaging Research Laboratory, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Received 9 September 2002; received in revised form 18 December 2002; accepted 18 December 2002.

Abstract

Objective

To evaluate changes in ovarian follicle dynamics during the human menstrual cycle to test the hypothesis that folliculogenesis occurs in a wave-like fashion.

Design

Prospective longitudinal study.

Setting

Healthy volunteers in an academic research environment.

Patient(s)

Fifty healthy women of reproductive age (range 19–43 years) with a history of regular menstrual cycles not taking medications known to interfere with reproductive function were evaluated.

Intervention(s)

Transvaginal ultrasonography was performed daily for one interovulatory interval (IOI).

Main outcome measure(s)

Changes in the diameter and number of follicles ≥5 mm were evaluated.

Result(s)

Sixty-eight percent of women exhibited two waves of follicle development during the IOI and 32% exhibited three waves. Waves were characterized by an increase and subsequent decrease in the number of follicles ≥5 mm occurring in association with the growth of ≥2 follicles to ≥6 mm. A day effect and day by wave interaction were detected in the mean diameter of the largest three follicles and the number of follicles ≥5 mm.

Conclusion(s)

The follicular wave phenomenon in women provides a new model for ovarian function during the menstrual cycle and will improve our understanding of the ovarian response to fertility and hormonal contraceptive regimens.

Keywords: Atresia, follicular waves, folliculogenesis, ovary