Women’s health experts have called for more research into female contraception and its benefits and side effects after a new study found millions of patients who use a hormonal contraceptive injection may have an increased risk of developing brain tumours.
Healthcare professionals have urged women taking progestogens not to panic and to speak with their GP before stopping any prescription medication.
It comes after research published in the British Medical Journal using French national database showed an association between certain progestogens and the risk of meningioma – a usually benign tumour of the membranes covering the brain and spinal cord.
According to the study, people using injectable medroxyprogesterone acetate for more than a year appear to have a higher risk of meningioma.
Experts have stressed the study has limitations, including that it is observational and cannot determine the hormones caused the tumours, while highlighting the need for further research into women’s health.
In a statement, the Faculty of Sexual and Reproductive Health (FSRH) said: “This study highlights the importance of research in this area and the FSRH would of course encourage and welcome further research into the links between contraception, its benefits, side effects and health risks.”
It added: “It is important that women do not stop their contraception based on these study findings as this may put them at risk of pregnancy, but we do advise speaking with your health care professional if you are concerned.”
Research into women’s health has been historically underfunded. As a result, women with debilitating conditions such as chronic UTIs, endometriosis and severe menopause symptoms, have suffered with pain and discomfort for years before getting an accurate diagnosis, let alone the right treatment where available.
In recent years, an increasing number of women have been prescribed hormone replacement therapy (HRT) for a range of symptoms associated with menopause. But the growing demand for the medication was met with UK-wide shortages.
British Menopause Society chair Dr Paula Briggs, told i the lack of research into women’s health means they suffer with a whole range of conditions that uniquely affect them, including fibroids and endometriosis.
She said: “Around menopause, particularly, there’s been such a huge amount of awareness raising that it’s almost become more apparent that there is less research in women’s health areas when compared with other areas.
“It’s not just women who suffer, it’s families as well. If we could direct more funding towards women’s health research, it doesn’t just improve the lives of women, it improves the lives of everyone.”
Dr Briggs highlighted the need for information about contraception to understood on balance.
She said: “I think for women who depend on social media for their information, some of what they’re seeing is extremely skewed. It’s not necessarily balanced information.
“Even with this study, we have to remember that meningioma are benign tumours, that there will be differential rates between men and women, so irrespective of what contraception is used.”
Dr Briggs also warned against the consequences of women abruptly stopping contraception.
She said: “If somebody would only use a contraceptive injection, I wouldn’t prevent them from doing that because of anxiety around the risk of the patient developing a meningioma.”
She said: “[A] downside to women becoming frightened of using hormonal contraception is unplanned pregnancy and the consequences of that are enormous.”
The research found no additional risk for progesterone, dydrogesterone or hormonal intrauterine systems, which Dr Briggs said are a “fantastic method of contraception” even though many women opt out of intrauterine devices (IUD) contraception because of fear about their insertion.
The large study used data from the French national health system for 18,061 women (average age 58) who underwent meningioma surgery from 2009-18.
Each case was matched to five control women without meningioma (total 90,305) by year of birth and area of residence.
Dr Mangesh Thorat, deputy director (clinical) of the Cancer Prevention Trials Unit at King’s College London, said the research does not give women using progestogens reason to panic.
Dr Thorat said: “Although this is a large study, all studies have limitations. This study could not investigate long-term exposure beyond a few years, or the over-the-counter use of contraceptives.
“Furthermore, the study cannot provide information on the formulations not commonly used in France but used in other countries. This therefore underscores the need for further research using similar databases in other nations.”
The French researchers, including from the French National Agency for Medicines and Health Products Safety, said: “In countries for which the use of medroxyprogesterone acetate for birth control is frequent (74 million users worldwide), the number of attributable meningiomas may be potentially high.”
The results showed that prolonged use of medroxyprogesterone acetate injection was associated with a 5.6-fold increased risk of meningioma.
While the tumour is usually benign, it can cause serious problems in some patients due to its location in and around the brain and spinal cord.
There are around 10,000 prescriptions for medroxyprogesterone acetate every month in England, NHS data suggest.
Paul Pharoah, professor of cancer epidemiology at Cedars-Sinai Medical Centre in the US, said around 40 out of 10,000 30-year-old women in the UK would be expected to be diagnosed with a meningioma before the age of 80.
“This increases to 200 in those who have used medroxyprogesterone acetate,” he added.
In a statement, Pfizer, which manufactures two medroxyprogesterone acetate injections used in the UK, Depo-Provera and Sayana Press, said: “Patient safety is Pfizer’s utmost priority. We ensure rigorous and continuous monitoring of all of our medicines, including the assessment of reported adverse events, in collaboration with the European Medicines Agency and health authorities in each country.
“We are aware of this potential risk associated with long-term use of progestogens and, in collaboration with regulatory agencies, are in the process of updating product labels and patient information leaflets with appropriate wording.”
Sarah Carter is a health and wellness expert residing in the UK. With a background in healthcare, she offers evidence-based advice on fitness, nutrition, and mental well-being, promoting healthier living for readers.
