PNH National Services

Pregnancy and Contraception


The safest methods of contraception are either the use of progesterone-implanted coils (like the Mirena coil) or using a barrier contraception (i.e. condoms).

The combined oral contraceptive pill should ideally be avoided as it can increase the risk of developing a blood clot.


Neither men nor women with PNH have reduced fertility specifically due to their disease. PNH is not an inherited disorder and there is no additional risk of the baby developing PNH. The major risk to the unborn baby is if the mother with PNH becomes unwell during pregnancy. It is therefore critical to closely manage pregnancy in women with PNH to prevent any potential complications (see below).


As a service, we have now supported many ladies with PNH through pregnancy and delivery. Pregnancy is however associated with an increased risk of complications in PNH. It is therefore important to discuss the decision to become pregnant at the PNH clinic if at all possible. In almost all patients with PNH, pregnancy is potentially high risk and will be followed much more closely by both the local obstetric team in collaboration with the PNH Centre to prevent complications occurring and to reduce this risk.

During pregnancy, it is important to be reviewed regularly both by haematology and obstetric specialists.

Treatment during pregnancy may include:

  • Blood and platelet transfusions.
  • Low molecular weight heparin (a drug to reduce the risk of developing blood clots).
  • Eculizumab – to commence if the PNH clone is over 20% or to dose adjust during pregnancy.
  • Planned delivery.