Editing Haemophilia (section)

=== During pregnancy ===
A pregnant woman with a history of haemophilia in her family can test for the haemophilia gene. Such tests include:
* chorionic villus sampling (CVS): a small sample of the placenta is removed from the womb and tested for the haemophilia gene, usually during weeks 11–14 of pregnancy<ref>{{Cite web |title=Chorionic villus sampling |url=http://www.nhs.uk/conditions/chorionic-villus-sampling/pages/introduction.aspx |publisher=[[National Health Service]] |date=20 July 2018 |access-date=10 February 2020}}</ref>
* amniocentesis: a sample of amniotic fluid is taken for testing, usually during weeks 15–20 of pregnancy<ref>{{Cite web |title=Amniocentesis  |url=http://www.nhs.uk/conditions/amniocentesis/pages/introduction.aspx |publisher=[[National Health Service]] |date=17 April 2019 |access-date=10 February 2020}}</ref>

There is a small risk of these procedures causing problems such as miscarriage or premature labour, so the woman may discuss this with the doctor in charge of her care.<ref name=NHS />