By Dr. Claire Harrison
Guy’s and St. Thomas’ Hospital, London, UK
I was very pleased to be asked to write on this topic. Just as there are gender differences in other aspects of life; specific concerns arise for women who have MPNs. Some of my colleagues thought the idea was “sexist” or “biased” but most also felt that acknowledging and focusing on areas specific to women was both unique and important. I hope that readers of both genders benefit from the content generated.
Interestingly, recent thinking about how and why MPNs occur has highlighted again that being a woman means you are more likely to present with a diagnosis of ET than PV or MF.
Many aspects of disease management are identical for both women and men but it is important to recognize that MPN may come to light in different ways. For example, a woman may suffer multiple miscarriages or particularly heavy periods due to an underlying MPN.
Another interesting observation from some of my own patients has been that their platelet counts tend to be higher during menstruation and some tolerate venesections very poorly at this time. Heavy menstruation needs to be assessed by a gynecologist but can be managed by reducing aspirin dose, low doses of clot stabilizing drugs or a hormone coated device such as the mirena coil.
The use of combined oral contraceptive either as contraception or to control excessive menstrual loss is not appropriate due to risks of venous thrombosis. Other forms of contraception such as the progesterone-only pill are acceptable. My advice regarding hormone replacement therapy is to use the lowest dose of oestrogen and to avoid it where there has already been a thrombosis.
Can I Get Pregnant and What Are the Risks?
We can answer most confidently that the chance of a successful pregnancy with ET is about 60-70%; slightly lower than for women with PV or PMF. The development of the placenta, much like the growth of the baby, can be monitored in pregnancy by use of ultrasound scanning to examine blood flow in the placental blood vessels. We recommend these at least once in pregnancy. The risks to the mother are of thrombosis and the risks here are largest in the first 6 weeks after the baby is born so extra precautions with heparin are usually advised at this time.
As with all pregnancies, the healthier the mother in general the more successful the pregnancy; and so it is important to maximize your health when planning to get pregnant. I would also add that planning to have your family when young where possible is best for a healthy pregnancy as all risks not only that of Down’s syndrome increase with age.
If pregnancy happens whilst taking hydrea or xagrid, get in touch with your hematologist and stop the drug as soon as safely possible, switching to interferon.
After pregnancy, blood counts return quite rapidly to their previous levels; sometimes they can overshoot. This overshoot may be risky and so remember to keep an eye on the blood count and how you are feeling. Remember also this is the time when blood clots happen even to women without MPN so we use heparin for the first 6 weeks and continue other treatments such as aspirin and interferon.
The aim of this article was to discuss issues specific to women who have MPNs. There are many inspiring stories about successful pregnancies with women who have MPN. One such story is included can be found here.