MPNs in pregnancy

MPNs and PregnancyMyeloproliferative neoplasms (MPNs) can increase the risks in pregnancy but planning makes a difference.

Many people may be diagnosed with an MPN in their twenties and thirties, the time in life when many of us are establishing careers and starting families. It can come as an unwelcome surprise to learn not only that you have an MPN, but that this disorder may affect your ability to start a family. You might have learned you had an MPN when you had your first blood test after becoming pregnant. Understandably, this news may have come as a shock.

The risks are real

MPNs can increase the risk of miscarriage both early and late in pregnancy. MPNs can also increase the risk of the mother developing pre-eclampsia, a dangerous condition in which a woman develops high blood pressure during pregnancy. Pregnant women who have MPNs need to be carefully monitored by their health care team including their haematologist, obstetrician and midwife to watch for and manage any problems that may develop.

The good news about MPNs in pregnancy

The good news is that having an MPN doesn’t have to prevent you from having children. The most important factor when you are thinking about starting a family is planning and working together with your health care team. It’s key to discuss your plans together with your haematologist and your GP before you become pregnant (if possible) and while you are pregnant.

After delivery

New mothers with MPNs can face medical and emotional challenges. The weeks after delivery (or after a miscarriage) can be a challenging time for women with MPNs. Your blood volume will decrease rapidly immediately after delivery and your blood counts may increase very fast to levels that may be high, even dangerous. Your haematologist will track you very carefully during this time to ensure that you stay healthy and safe.

Treatment options

New mothers with an MPN are at risk of clots after delivery. This is because blood volume decreases rapidly after delivery. New mothers with MPN may need to take heparin to prevent clots. This drug which is given by injection for several weeks after delivery is easy to self-administer or you can ask a family member for help. In addition to heparin, some new mothers need to continue with interferon therapy or may need to return to hydroxycarbamide or another cytoreductive drug. In some cases taking medication may mean that you will not be able to breastfeed.


Some new mothers may not be able to breastfeed their baby if they need to take medication after delivery. Heparin is safe but hydroxycarbamide, anagrelide and other cytoreductive drugs can harm a baby if passed through the breast milk. The risks with interferon are less clear and you may be able to continue to breastfeed while on this drug but it would be important to discuss this with your own team. It can be upsetting to learn you cannot breastfeed if you hoped to breastfeed your child. You may also feel pressure from family members or other well-meaning people who would prefer that you breastfeed your baby. In all cases the most important consideration is the long-term health of both mother and baby. Talk with your midwife and doctor about your options. You may wish to talk with a buddy if this is upsetting or a difficult decision for you.

Incision healing

If you have had a caesarian section you might continue to bleed from your incision for some time, particularly if you are taking heparin. If bleeding is profuse, do not hesitate to ask your haematologist and GP for help. Keep your incision covered with sterile gauze bandages. Special tape is available that does not hurt your skin. Some mothers with MPNs have found that sterile, medical seaweed-based “packs” can assist in closing an incision. Ask your GP for advice.

Serious fatigue

Having a baby is always tiring, but fatigue can be a particular problem if you lost blood during delivery, if you continue to bleed after delivery, and if your baby was born early or small and requires around-the-clock care. It is very important to take good care of yourself during this time and to actively plan to have others help you. Consider hiring help if you can afford it, for instance a doula or a child-minder to help with older children. Ask for help from family members and friends. You may need extra help during the night so that you can get a few more hours of sleep. Ask your partner or another family member to give your baby a bottle feed with formula during the night so that you can recover and heal. Talk with your haematologist and your GP if you need help in coping with fatigue.

Visit the section coping with fatigue for more practical tips about fatigue.