Brown, J. B. (2011). Types of ovarian activity in women and their significance: the continuum (a reinterpretation of early findings). Human Reproduction Update, 17(2), 141-158. https://doi.org/10.1093/humupd/dmq040
Brown JB. Types of ovarian activity in women and their significance: the continuum (a reinterpretation of early findings). Hum Reprod Update. 2011;17(2):141-158. doi:10.1093/humupd/dmq040
Brown, James B. "Types of ovarian activity in women and their significance: the continuum (a reinterpretation of early findings)." Human Reproduction Update, vol. 17, no. 2, 2011, pp. 141-158.
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Women's ovarian activity moves along one continuum of fertility
Every type of ovarian activity in women fits one continuum, from no activity to full fertility. This 2010 review re-reads old urine hormone studies of girls, new mothers and women nearing menopause. Fertility can shift up or down at any time, and stress is a major cause. Only a fully fertile cycle can produce a continuing pregnancy.
Key Findings
Five steps run from no ovarian activity, through anovulatory activity and a luteinized unruptured follicle (LUF), then ovulation with a deficient or short luteal phase, to a fully fertile ovulatory cycle.
Of 140 ovulatory cycles, 60 showed a brief pre-ovulatory progesterone-marker rise that met the criteria for a LUF, and 51 of those came with early estrogen peaks.
Among 55 postpartum women, all types of ovarian activity appeared. Breastfeeding and time since delivery influenced how often each type occurred.
Five of ten elite women rowers showed changes in menstrual function across a year of varying training intensity. One rower's cycles returned to fully fertile within months of easing training.
Ten of 140 ovulatory cycles (7%) had a deficient luteal phase. Deficient and short luteal phases were the most common infertile ovulatory cycles.
Interpretation
The paper is a narrative review that re-presents hormone measurements from studies done between the 1950s and 1970s. Most evidence comes from individual women followed closely and shown as case examples, plus a few small groups. The author reports stress as the most important factor moving ovarian activity from fertile to infertile types. The author cites a Harvard study of ten rowers and case examples in support, and the review tests stress directly nowhere. The author describes the five steps as a continuous process.
RRM Context
Cycle charting reads the same hormone changes through daily body signs. The author reports that the Billings Ovulation Method identified fertile and infertile stages across the continuum. A cycle that looks ovulatory can still fall short of fertility. Restorative reproductive medicine looks for that cause first.
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
There are many types of ovarian activity that occur in women. This review provides information on the relationship between the hormone values and the degree of biological response to the hormones including the frequency and degree of uterine bleeding. The continuous process is termed the 'Continuum' and is thus similar to other processes in the body.
Methods
This review draws on information already published from monitoring ovarian activity by urinary oestrogen and pregnanediol measurements using timed 24-h specimens of urine. Much of the rationalization was derived from 5 to 6 year studies of girls progressing from childhood to adulthood, women progressing through menopause, and the return of fertility post-partum. During these times, all the reported types of ovarian activity were encountered.
Results
All cycle types can be understood in terms of steps in the normal maturation of fertility at the beginning of reproductive life, its return post-partum and its demise at menopause. Each step merges into the next and therefore the sequence is termed the 'Continuum'. Unpredictable movement from fertile to infertile types and back can occur at any time during reproductive life. Stress is a major causative factor. Hormonal definitions for each step, the relevance of the various cycle types in determining fertility and in the initiation of uterine bleeding and the roles of the pituitary hormones in causing them, are presented.
Conclusions
The findings explain the erratic fertility of women and why ovulation is not always associated with fertility. They provide an understanding of the various types of ovarian activity and their relation to pituitary function, fertility and uterine bleeding.
Reproductive Endocrinology › Ovarian Hormones › Estrogen · Menstrual Cycle › Cycle Across the Lifespan › Cycle and General Health · Longevity and Reproductive Aging › Reproductive Aging › Cycle Changes With Age
James B Brown
Jim Brown, Jimmy Brown, J Brown
PMID 20923873 20923873 DOI 10.1093/humupd/dmq040 10.1093/humupd/dmq040 Brown et al. 2011, Brown 2011
01ej9dk98 