A new study published in the BMJ has looked at the different types of HRT treatment and the potential risk of blood clot (also known as venous thromboembolism or VTE).

HRT, or hormone replacement therapy, can be prescribed to help women experiencing symptoms of the menopause, such as hot flushes and night sweats.

Previous studies have demonstrated an increased risk of VTE for women using HRT treatment when compared to those not exposed to treatment. However, the studies have been unable to provide comparisons between treatment types.

How was the study carried out?

Researchers at The University of Nottingham have looked at the prescription records of 80,000 women aged between 40 and 79 and diagnosed with a blood clot. This group was then compared with the records of 390,000 women who had not been diagnosed with blood clots.

What did the outcome of the study show?

According to this study, oral HRT medications containing conjugated equine oestrogens had a slightly higher risk of blood clots when compared to other treatments, and compared to no exposure. HRT containing oestradiol and dydrogesterone had the lowest risk.

Conjugated equine oestrogen is used in some HRT medications such as Premarin, an oestrogen-only tablet medication, and Premique, a combined HRT tablet.

The study also showed that oral HRT treatments continue to be the most favoured form of treatment.

Due to some limitations with this study, the findings are unable to prove a direct causal link between HRT use and VTE risk. However, the results are still extremely interesting, especially for prescribing clinicians and for women looking for help with menopausal symptoms.

The study’s conclusion also stressed that the presence of comorbidities or obesity in patients should indicate further discussion of transdermal HRTs, an action that is in line with the current NICE guidelines. Transdermal HRT treatments, which include patches applied to the skin and gels, are thought to carry a lower risk of blood clots than oral treatments.

What other HRT treatments are there?

HRT is available in a variety of forms. Not all HRT products will suit all women. Some are intended for women who are perimenopausal (going through the earlier stages of the menopause) and others for postmenopausal women. It is important to have a thorough conversation with your doctor before a treatment course is commenced.

The results have indicated that transdermal HRT treatments such as patches, creams and gels did not show an increased risk of venous thromboembolism. The study’s conclusion noted that these types of HRT medications appear to be underused when compared with their oral tablet alternatives.

Where can someone go for more info?

If you are taking HRT and want to discuss the benefits and risks of treatment, including those raised in this study, your doctor will be able to help. Patients currently taking HRT should not panic or make any changes to their medication without consulting their GP first. Any concerns raised due to the results of this study should be looked at with a patient’s GP at their next routine appointment.

You can find more helpful information on our page: Which HRT is best for me?