Contraceptives and HRTMyeloproliferative neoplasms (MPNs) are usually diagnosed in older patients, but people who are young enough to conceive need to consider their contraceptive choices carefully, whilst women approaching menopause and offered hormone replacement therapy (HRT) also need to be informed of the potential added risks of HRT. Contraceptives - considerations/risks As with any decision concerning contraception for a patient with any type of MPN it is important to carefully consider your options. For women and men especially those taking drugs other than aspirin to control their MPN, it is important to think about contraception. For men this is because most doctors would advise against your partner becoming pregnant while you are taking a drug such as hydroxycarbamide or other drugs, all forms of male contraception are suitable for use. For women with an MPN the question is more complex as having an MPN means certain types of contraception are less suitable. In particular the combined oral contraceptive pill, also known as “the pill” or COCP containing both oestrogen and progesterone, two important female hormones, is not suitable because the hormones are present at higher levels than normal and the oestrogen is especially linked to a risk of blood clots. For this reason other contraceptives should be used and the good news is they are all suitable for women with MPN. Hormone replacement therapy – weighing up the benefits/risks Hormone replacement therapy or HRT which is generally used by women at/around the menopause has been controversially associated with several risks including heart disease over the years. Nowadays the levels of hormones in HRT are much lower than they were in the past and especially lower dose regimes may be acceptable for women with MPN. However this will need to be an individual decision based upon factors such as family history of breast or ovarian cancer, history of blood clots etc. It will be important to involve both your haematologist and your family doctor or gynaecologist in these decisions.