What science tells us about surgical menopause
How can research inform our care in surgical menopause? We asked Dr Sally Doust to take a look and break down the latest studies.
What the Research Shows Us
Surgical menopause isn’t just an abrupt end to periods – it’s an abrupt change in our biology. When our ovaries are removed, the loss of oestrogen, progesterone and testosterone affects almost every system in our body. For decades, research has shown that this sudden deprivation can have a long term impact on our health, but also that replacing those hormones dramatically reduces the long term health risks and can also help to manage the short term symptoms that many of us will experience rapidly, and severely, in the hours, days and weeks after surgery.
Key Facts
Surgical menopause before 45 is linked with increased mortality, heart disease, and cognitive decline.
These risks are preventable with timely hormone replacement.
Fewer than 1 in 20 UK women receive HRT after surgery despite clear guidance.
Body-identical HRT (17β-estradiol and micronised progesterone) offers the safest and most effective replacement.
The science overwhelmingly supports individualised, hormone-based aftercare for every woman who undergoes ovary removal.
Key Research Studies
Below, we’ve summarised the most influential studies shaping current understanding of surgical menopause and hormone therapy.
Long-term health consequences after ovarian removal at benign hysterectomy
Gottschau M, et al. (2023) –Annals of Internal Medicine, 178(4). DOI: 10.7326/M22-1628
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This Danish population study followed over 30,000 women who had their ovaries removed during non-cancer hysterectomy. It concluded that ovary removal is linked to higher long-term rates of cardiovascular and metabolic disease, confirming that the ovaries continue to protect health well beyond fertility.
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Nationwide Danish cohort of > 30,000 women.
Oophorectomy increased later cardiovascular and metabolic disease risk.
Confirms ovaries have ongoing protective value beyond fertility.
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Study Quality:
Followed a large cohort of women and looked at removal of ovaries for benign conditions rather than cancers. Presumably a representation of the general population because they used population data.
Limitations:
Age was a proxy for menopause status (ie we didn't actually know whether women were peri- or post-menopausal at time of surgery) which may have influenced results.
Long-term health consequences of
premature or early menopause
Faubion SS, Kuhle CL, Shuster LT, Rocca WA (2015) Climacteric, 18(4):483-491. DOI: 10.3109/13697137.2015.1020484
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This landmark Mayo Clinic review examined how the early loss of ovarian hormones affects long-term health and lifespan. It concluded that early menopause – surgical or natural – increases cardiovascular, bone, cognitive, and mental health risks, and that oestrogen replacement until at least the average menopause age restores protection.
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Women who lose ovarian function before natural menopause face higher risks of cardiovascular disease, osteoporosis, depression, and cognitive decline.
Early oestrogen replacement until at least age 51 reduces those risks and restores life expectancy to normal levels.
Authors advocate proactive, individualised hormone therapy for women with surgical menopause.
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Study quality:
The first author is an experienced researcher in sex-based differences in health.
Limitations:
This was a narrative review, meaning that it selected studies based on the writers' judgement, and did not exhaustively search all the existing studies out there. The studies included used different statistical methods and varying ways of measuring how significant the results were.
Treatment of women after bilateral salpingo-oophorectomy prior to natural menopause
Kaunitz AM, Kapoor E, Faubion SS (2021) –JAMA, 326(14):1429-1430. DOI: 10.1001/jama.2021.3305
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Published in JAMA, this paper provided practical recommendations for caring for women after ovary removal. It concluded that oestrogen therapy should start immediately after surgery where there are no contraindications to its use, and continue to around age 51 to reduce the risk of heart disease, dementia, and early death.
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Immediate HRT after surgery is vital, even without symptoms.
Transdermal oestrogen is the preferred route for safety and efficacy although it advised that women’s choices should be taken into consideration when discussing HRT regimen
Continuing therapy until at least natural menopause age significantly reduces heart, cognitive and mortality risks.
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Study Quality:
All 3 authors are highly eminent. The first author is a professor of O&G who has published more than 300 research papers.
Limitations:
This is an expert opinion piece, so it does not assimilate data from multilple studies or analyse the significance/statistical strength of the findings in studies quoted.
Comments:
“The most striking fact to me in this paper was 'among 3002 women younger than 51 years who had undergone bilateral salpingo-oophorectomy (BSO) from 2013 to 2014, 23% had histologically normal ovaries.”
Association between bilateral salpingo-oophorectomy and all-cause and cause-specific mortality
Cusimano MC, Simpson AN, Han A, et al. (2021)BMJ, 375:e067528. DOI: 10.1136/bmj-2021-067528
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This large Canadian cohort study followed more than 200,000 women for 12 years, to explore how age at ovary removal impacts mortality. It found that women who had surgery before 45 had a 31% higher risk of death, but that risk disappeared after 50 – confirming that both age and hormone replacement are crucial.
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Study of over 200,000 Canadian women.
Ovary removal before age 45 increased overall mortality by 31%.
No increased risk if the surgery was after age 50 – highlighting age and hormone status as critical factors.
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Study Quality
The study authors do not comment on the ethnicity or socio-economic status of the study participants.
Limitations
The study excluded women who'd had the surgery to remove cancers, so findings are not as applicable to those women. It also means that mortality results in this study may actually be lower than if women with cancers had been included (because they might have died if their cancer recurred).
Hazard ratios (the measure of risk used in this study) show association rather than causation so it might be more clear to say 'surgery before 45 was linked to/associated with a 31% higher risk of death'
In addition, this is 'all cause mortality' – this means that it's linked to a higher risk of death from any cause.
Audit of hormone replacement therapy use following bilateral oophorectomy in premenopausal women
Cashell C, Newson L, Glynne S, et al. (2024)
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A five-year NHS audit measuring how often women received HRT after surgery. It revealed that only 4.8% of eligible premenopausal women were prescribed HRT, exposing a major care gap and underscoring the need for better clinical training and consistent post-operative guidance (and something SURGE Menopause advocates for, too).
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Five-year NHS audit across three hospitals.
Only 4.8 % of eligible premenopausal women received HRT after ovary removal.
Authors call for national training and patient education to close this critical care gap.hormone status as critical factors.
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Study Quality
A powerful study that shows rates of low planned proper HRT care.
Limitations
The audit does not include any information on whether the women included had had surgery for cancers or not. It will often (not always) be very unsafe for women with ovarian cancer for example to receive HRT. It would have been better to break down the data to distinguish between women with and without cancer.
Even so, the statistics are very powerful and it's very likely that even if cancer patients were excluded from the data, the rates of planned proper HRT care would be extremely low.
Risk-reducing salpingo-oophorectomy and the use of HRT below the age of natural menopause
Manchanda R, Gaba F, Talaulikar V, et al. (2021) BJOG, 128(13):2143-2153. DOI: 10.1111/1471-0528.16896
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This Royal College of Obstetricians and Gynaecologists-backed review examined HRT use after preventative ovary removal in women with BRCA or Lynch gene mutations. It concluded that HRT is safe for women under 51 without prior breast cancer and should begin immediately post-surgery.
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Guidance for BRCA and Lynch gene carriers undergoing risk-reducing surgery.
HRT is safe for women under 51 without prior breast cancer.
Hormones should start immediately post-surgery and continue until at least the average menopause age.
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Study Quality
Published in a high quality peer reviewed journal and in association with a national professional body. It is clear that the overriding consensus is that early surgical menopause has severe consequences and use of HRT is of clear importance.
Limitations
This is an expert review and opinion piece. It comments on the currently available body of research on BRCA gene carriers, which is limited to some observational studies (rather than large randomised controlled trials). In some specific areas (like vaginal treatments and very high risk women) there is a very limited evidence base. It calls for more research and explains that treatment decisions should be made on an individual basis.
The range and variation in serum estradiol levels achieved by licensed transdermal estradiol preparations
Glynne, S. J., Cashell, C., Newson, L. R., Pearce, E., Bailey, L., & Samuel, M. (2025) Menopause, 32(2), 000–000. DOI:10.1097/GME.0000000000002312
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A UK study assessing how effectively different forms of transdermal oestrogen are absorbed across the skin. It found that even at the highest licensed doses, up to one in four women had low oestradiol levels, highlighting why individualised, off-label dosing is often necessary to achieve symptom relief and health protection.
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Significant variation in oestrogen absorption across the skin.
Up to 1 in 4 women had sub-therapeutic levels despite highest licensed doses (100 µg patch / 4 pumps gel).
Supports personalised dosing and use of off-label regimens when clinically indicated.
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Limitations
This is an important piece of research to discuss in terms of limitations.
This was a study done on private clinic patients (so an unrepresentative population) and it also does not comment on timings of blood collection which is extremely problematic.Questions that the study does not clarify are:
Was the sample taken from a site contaminated with oestrogen on the skin?
Were the samples taken at peak (after HRT dose is absorbed) or trough (24 hours after HRT dose, before next one is due)? This is not specified in the study.
Furthermore, the general consensus amongst medical professionals about measuring serum oestradiol is reluctant/sceptical at best.
A summary of the current professional consensus is:
Serum estradiol is not a true indication of oestrogen activity in the body;
We cannot tell the difference between endogenous (woman's own) and exogenous (HRT) estradiol;
We may possibly be able to correlate serum estradiol to adequate absorption of HRT if timing of blood sampling is consistent;
We are unlikely to be able to correlate serum estradiol with clinical symptoms;
There is no agreed threshold in serum estradiol for optimal HRT for treatment/symptom management
Concerns
You may be aware that this private clinic, Newson, received negative press for going above licensed doses of oestrogen for women and potentially causing harm.
I absolutely agree that on an individual basis for younger women having undergone surgical menopause they may often need higher doses of oestrogen; but arguably that should not be a decision based on this study's findings.