July 2, 2026

expert reaction to study looking at contraceptive progestogens and meningioma brain tumours

A study published in JAMA Network Open looks at contraceptive progesterone and the incidence of meningioma brain tumours. 

Prof Paul Pharoah, Professor of Cancer Epidemiology, Cedars-Sinai Health Sciences University, said:

“This paper reports on an analysis of routinely collected data from the population in Denmark to evaluate the association between hormonal contraception use and meningioma occurrence in women.  There is strong evidence that certain types of progestogens are associated with an increase in risk of meningioma, but an association for some types of progestogens that are used in different formulations of the hormonal contraceptives has not been established.

“This study has been carefully carried out and analysed.  The findings were similar to previous studies, with the strongest association for medroxyprogesterone injections (a relative increase in risk of about 4-fold) and a weak association for several other progestogens (relative increase in risk about 1.5-fold).  Importantly they found that this risk only persisted while the women were using the hormonal contraceptive and declined once they stopped.

“This is an observational study and determining that the observed associations are causal is difficult as it is hard to exclude all possible confounders.  However, given all the available evidence it seems likely that the association is causal.

“While a 4-fold relative increase in risk seems very high, the absolute risk of meningioma is small.  About 5 women per 1000 will develop a meningioma in their lifetime.  This increases to 6 per 1000 for a woman using medroxyprogesterone from age 25 to 44 (the highest risk contraceptive).  The increase in risk for other hormonal contraceptives is very small.  These very small increases in risk need to be balanced against the benefits of different forms of contraception.  It is important that women do not stop using their birth control pills without consulting their doctor.”

Prof Channa Jayasena, Professor of Reproductive Endocrinology, Imperial College London, said:

“Contraceptives contain either drugs acting like oestrogen plus progesterone (‘the combined contraceptive pill’), or just progesterone alone (‘the mini-pill’).  They work by suppressing activity of the ovaries and womb to prevent pregnancy, and form a vital role in society for women who want to avoid pregnancy.

“We have known for a few years that high dose exposure certain progesterone drugs increase risk of meningioma.  Meningiomas are tumours of the lining of the braining.  Most meningiomas have receptors that can ‘listen to’ progesterone in the body, so it is plausible that any type of progesterone-like drug could slightly increase the risk.

“The investigators looked a case-notes from 3 million women across Denmark.  They found that 1 in 2000 women developed a meningioma.  By far the strongest risk factor for meningioma was increasing age.  However, nearly all types of combined or mini pill were associated with an increased risk of meningioma, but not by much in absolute terms – this might be the same as converting a 1 in 2000 risk to 1 in 1000-1500.  It is interesting that injectable forms of progesterone were associated with a higher risk than other forms, but even that increased the risk to the equivalent of on 1 in 400-500.

“All medications have risk, and contraceptive medications are no different.  As the paper correctly states, the overall chance of these drugs giving you a meningioma is tiny.

“Also, this study did not look at HRT which uses much lower doses of progesterone, so is not expected to increase meningioma risk.  Therefore, these results do not apply for women taking HRT.”

Comments from our colleagues at the Australian SMC:

Alex Polyakov is a Clinical Associate Professor from the Faculty of Medicine at the University of Melbourne and Medical Director of Genea Melbourne:

“Meningiomas are the most common primary intracranial tumour in adults, and although more than 95% are histologically benign, their mass effect within a fixed cranial space means they can cause seizures, focal deficits, and cognitive impairment, often requiring surgery or radiotherapy. Their consistently higher incidence in women, together with progesterone receptor expression, has long suggested that hormones contribute to their development. This Danish study asks which specific progestogens, at contraceptive doses, actually increase the risk.

The study design relies on Denmark’s linked national registers, which provide complete prescription records, validated cancer diagnoses, and eliminate recall bias. This approach is appropriate given how rare meningiomas are in reproductive-age women. It lets the authors examine many small exposure groups while matching on age, birthplace, and marital status, and, importantly, model time since exposure. That last point is significant because the research shows risk is concentrated in current and recent users and largely resolves within five years of stopping.

The increase in risk is very small for most types of progestogens. The number of women who need to take these compounds to develop one extra meningioma runs from the hundreds of thousands into the millions per year of use, and these numbers are most reassuring in younger women. To put it in perspective, the chance of dying on our roads is about 1 in 20,000. The chance of dying from a meningioma is less than 1 in 500,000.

The clinical bottom line depends on assessing this research considering what contraception delivers, namely: prevention of unintended pregnancy, reduced ovarian and endometrial cancer risk, and management of heavy or painful periods. For combined pills and Intra-Uterine Devices (IUDs), the absolute excess risk is negligible and shouldn’t change clinical practice.”

Alex has not declared any conflicts of interest.

Gino Pecoraro OAM is Associate Professor of Obstetrics and Gynaecology at the University of Queensland and past president of the National Association of Specialist Obstetricians and Gynaecologists (NASOG). He is also a practising obstetrician and gynaecologist in private practice in Brisbane:

“This large population-based health register study provides further evidence of an association between progestogen exposure and meningioma. This association has been previously described and almost 90% of these usually benign tumours have progesterone receptors.

Meningioma occurs in roughly one in 10,000 people, with women having roughly double the rate that men do. It is well known that meningiomas grow during pregnancy and if extra progesterone is given, but decrease in size once the pregnancy is completed or progesterone withdrawn.

This study found an increased association with use of all of the currently available commercial progestogens to varying degrees.

The highest odds ratio 1.73 was found with injectable medroxyprogesterone acetate and the lowest odds ratio 1.14 was with IUDs with low-dose levonorgestrel. Progesterone-containing IUDs were previously thought not to increase the risk. The increased risk persists for up to five years after stopping the progestogen-containing treatment.

It is important to point out that a pregnancy in the preceding year also increases the risk of meningioma and carries other potential risks.

While interesting, it is important to point out that prevention of unwanted pregnancy is a major health issue.

Pregnancy in Australia carries a maternal mortality rate of 6.6 per hundred thousand, while the Australian five-year survival rate following meningioma diagnosis is greater than 90%.

Prescribers should certainly be aware of the association between progestogen exposure and meningioma and also of non-progestogen-containing contraceptive options, including barrier methods and copper-containing IUDs should this association be of concern to the woman.

This is further evidence of the importance of appropriate contraceptive consultations addressing risks and benefits of various means of contraception, taking place between prescribers and women, prior to writing a script or making a recommendation.”

Gino has not declared any conflicts of interest.

‘Contraceptive Progestogens and Incident Meningioma’ by Nicklas Hasselblad Lundstrøm et al. was published in JAMA Network Open at 16:00 UK time on Thursday 2 July 2026.

DOI: 10.1001/jamanetworkopen.2026.22603

Declared interests

Prof Paul Pharoah: “I have no conflicts of interest to declare.”

Prof Channa Jayasena: “No conflicts.”