Many people have heard of the word deep vein thrombosis, and it means when a blood clot develops in in the deep veins of the leg. occasionally in some people these clots can break off and travel up to the lung and these clots are known of pulmonary embolism. 

Unfortunately, some women are more risk of these clots forming due to underlying clotting abnormalities such as factor V lieden, but pregnancy, being on the combined oral contraceptive pill, being obese and a smoker increase the risks of these things happening and can other things such as immobility due to recent operation and long haul travel.

Recent evidence has suggested that there is a small risk of a blood clot associated with oral HRT preparations and this is because it is processed in the liver and increases to the stickiness of our blood meaning clots can form.

The kind of HRT that I commonly prescribed is transdermal HRT which does not increase your risk of developing a deep vein thrombosis or pulmonary embolism and if endometrial protection is needed, that is usually coupled with micronized progesterone (please see the attached leaflet on this). Which again, has no increased risk of DVT.

Sometimes after discussion with a lady, if she chooses oral hormone replacement therapy , at that point, we will talk about the type of progestogen used in the oral HRT as there are some that are associated with an increased risk of DVT (these are medroxyprogesterone acetate (MPA), dydrogesterone, levonorgestrel, or drospirenone. This is because They are synthetic progestogens as opposed to natural or body identical progesterone.

It is important though To understand how small this risk is, imagine a healthy woman of 50 years of age; she has a VTE risk of around 6 in 10,000 per year. If she took oral oestrogen tablets, this would double her risk to around 12 in 10,000 but it’s still a small risk overall.

Women with clotting abnormalities, Systemic Lupus erythematosus, antiphospholipid syndrome and who have previously had a DVT/PE can safely take the right HRT to manage their menopausal symptoms if they choose to.