In PNH, pregnancy is associated with a risk of complications. This is partly due to the fact that the risk of developing a blood clot during pregnancy is higher anyway. Therefore, this risk is compounded with PNH where blood clots are also possible. In rare cases, pregnancy may not be advisable however this should be discussed individually with your haematologist. It is important to inform your doctors if you intend to become pregnant as additional considerations may need to be taken into account. In almost all patients with PNH, pregnancy is potentially high risk and will be followed closely by your PNH doctors as well as an obstetric team to prevent complications and reduce risk. Additional treatments during pregnancy may include blood and platelet transfusions, folic acid, heparin and eculizumab. It is important to be reviewed regularly by a haematologist and obstetric teams.
As PNH is not inherited there is no risk of passing PNH on to a baby. Tests have shown that eculizumab does not cross the placenta or enter breast milk.
This 2014 scientific paper concluded that eculizumab appears safe to use in pregnancy in PNH and does not appear to cross the placenta in significant levels to block complement of the baby or to be excreted in breast milk. Higher doses of eculizumab may be required later in pregnancy to prevent haemolysis.
Dr Kelly from St James’s Hospital, Leeds talks about this important study
Neither men nor women with PNH have reduced fertility specifically due to the condition. However, long term illness or previous treatment may reduce fertility. Young men with PNH may find it difficult to maintain an erection but there are now effective treatments for this problem.
The safest methods of contraception are the progesterone only pill, mirena coil or barrier contraceptive methods eg. condoms. The combined oral contraceptive pill, which contains oestrogen, should be avoided as it can increase the risk of developing a blood clot.