Understanding the STRAW + 10 Framework
To standardize the understanding of female reproductive aging, the Stages of Reproductive Aging Workshop (STRAW) framework was developed and later updated to STRAW + 10 [1]. This system divides a woman's reproductive lifespan into three main phases, further broken down into substages [1]: the reproductive phase, the menopausal transition phase, and the postmenopause phase.
Phase 1: The Reproductive Years (Stages -5 to -3)
This phase begins with menarche. It includes the years of highest fertility and typically regular menstrual cycles [1, 2].
Early and Peak Reproductive Stages (Stages -5 and -4)
These stages are characterized by regular cycles and high fertility, with stable levels of key reproductive hormones like FSH, AMH, and inhibin-B [1].
Late Reproductive Stage (Stage -3)
The first subtle signs of aging may appear here. Ovarian reserve begins to decline, and while cycles are often still regular, AMH and inhibin-B levels start to decrease. FSH may show slight variations [1].
Phase 2: The Menopausal Transition (Perimenopause) (Stages -2 and -1)
This phase involves significant hormonal fluctuations, often starting in a woman's mid-to-late 40s. It leads to more noticeable symptoms [1, 2].
Early Menopausal Transition (Stage -2)
A key marker is a change in menstrual cycle length by seven or more days. FSH levels rise and become more variable as ovarian response declines [1].
Late Menopausal Transition (Stage -1)
This stage often involves intensified symptoms and longer intervals between periods (60+ days of amenorrhea). Fluctuating estrogen and progesterone cause symptoms like hot flashes, sleep disturbances, and mood swings [1, 2].
Phase 3: Postmenopause (Stages +1 and +2)
Beginning after 12 consecutive months without a period, this phase lasts for the rest of a woman's life. Hormone levels stabilize at low levels, and transitional symptoms generally subside [1, 2].
Early Postmenopause (Stage +1)
This stage starts after the final menstrual period. FSH remains high, and estradiol is low and stable. While hot flashes may continue, they often decrease over time [1].
Late Postmenopause (Stage +2)
Focus shifts to age-related changes and potential long-term health risks due to low estrogen, such as osteoporosis, cardiovascular disease, and urogenital atrophy [1, 2]. Acute symptoms typically resolve [1].
Key Hormonal and Physical Changes During Reproductive Aging
- Ovarian reserve: The number of eggs declines, accelerating in the late 30s [2]. Egg quality also decreases with age [4].
- Hormone fluctuations: Erratic estrogen and progesterone during the transition cause various symptoms [2]. Postmenopause is marked by low, stable levels [1, 2].
- Bone density: Declining estrogen reduces bone density, increasing osteoporosis risk after menopause [2].
- Cardiovascular health: Changes in lipid metabolism linked to lower estrogen may increase heart disease risk postmenopause [2].
- Urogenital changes: Lower estrogen can thin and dry vaginal walls, leading to genitourinary syndrome of menopause (GSM) [2].
The Difference Between Perimenopause, Menopause, and Postmenopause
| Feature | Perimenopause (Menopausal Transition) | Menopause | Postmenopause |
|---|---|---|---|
| Timing | Years leading up to the final period | A single point in time after 12 consecutive months without a period | The rest of a woman's life after menopause |
| Hormones | Fluctuating and erratic | Low and stable | Low and stable |
| Ovulation | Erratic, but still possible | Ceases | Ceases |
| Symptoms | Intense and variable (hot flashes, mood swings, irregular periods) | Marks the end of transitional symptoms | Many symptoms subside, but long-term effects (e.g., vaginal dryness) may persist |
| Fertility | Declining but still possible | Ends completely | No longer possible |
The Male Perspective on Reproductive Aging
Men also experience reproductive aging, though it differs from the female process. Male fertility declines gradually with age, involving decreased sperm quality and quantity, lower testosterone, and changes in sexual function. This process lacks a clear endpoint like menopause. The American Society for Reproductive Medicine provides resources on this topic [3].
Conclusion: Navigating the Reproductive Lifespan
Understanding what are the stages of reproductive aging? provides valuable insight for managing health throughout life [1, 2]. Recognizing the hormonal and physical changes characteristic of each stage, from the reproductive years through the menopausal transition and into postmenopause, allows for proactive health management, addressing symptoms, and mitigating long-term risks [1, 2]. This knowledge empowers women to make informed decisions and maintain well-being at every phase.
