Related Experiment Video
Updated: May 2, 2026
Orthotopic Ovarian Transplantation Procedures to Investigate the Life- and Health-span Influence of Ovarian Senescence in Female Mice
Published on: February 12, 2018
Is unilateral oophorectomy associated with age at menopause? A population study (the HUNT2 Survey)
E K Bjelland1, P Wilkosz, T G Tanbo
1Health Services Research Centre, Akershus University Hospital, N-1478 Lørenskog, Norway.
Study Question:
Is unilateral oophorectomy associated with age at menopause?
Summary Answer:
Women who had undergone unilateral oophorectomy entered menopause 1 year earlier than women with two ovaries intact.
What Is Already Known:
There is substantial variation in age at natural menopause. Unilateral oophorectomy implies a significant reduction of the ovarian follicular reserve. Thus, one might expect that the time to menopause is shortened by several years in women who have undergone unilateral oophorectomy.
Study Design, Size And Duration:
A retrospective cohort study of 23 580 Norwegian women who were included in the population-based HUNT2 Survey during the years 1995-1997.
Participants/Materials, Setting, Methods:
Data were obtained by two self-administered questionnaires at study inclusion. Cox proportional hazard models were used to estimate relative risks of menopause according to unilateral oophorectomy status with and without adjustment for birth cohort, parity, smoking, body mass index (BMI) and age at menarche.
Main Results And The Role Of Chance:
Women who had undergone unilateral oophorectomy were younger at menopause [mean 49.6 years; 95% confidence interval (CI): 49.2-50.0] than women without unilateral oophorectomy (mean 50.7 years; 95% CI: 50.6-50.8) (P < 0.001). The crude relative risk of menopause was 1.28 (95% CI: 1.15-1.42) and remained similar after adjustment for the study factors above (adjusted relative risk 1.27; 95% CI: 1.14-1.41). In addition, recent birth cohort and high BMI were associated with higher age at menopause.
Limitations, Reasons For Caution:
Information on unilateral oophorectomy was based on self-reports. Some women may therefore have been misclassified.
Wider Implications Of The Findings:
Although the effect of unilateral oophorectomy on the age at menopause is similar to that of smoking, it is weaker than anticipated from the loss of ovarian follicular reserve. Thus, compensatory mechanisms may occur in the remaining ovary.
More Related Videos
05:32Author Spotlight: Investigating the Relationship Between FSH and Pathophysiological Changes in Perimenopausal Women - Insights from a Mouse Model
Published on: August 11, 2023
05:42Z-Scores for Assessing Ovarian Reserve in Young Patients Undergoing Fertility Preservation
Published on: October 25, 2024
Related Concept Videos
01:28Menopause
02:07Oogenesis
01:30Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
02:20Longitudinal Research
01:22Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH...
01:29Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...