Every woman reacts to pregnancy differently. In pregnant women with asthma, asthma control improves in about 1 in every 3 women, worsens in about 1 in every 3 women and remains the same in about 1 in every 3 women.
Worsening of asthma symptoms can happen at any stage of pregnancy, but it seems to be most common between 17 and 36 weeks, mainly in the 6th month of pregnancy.
Asthma can also begin again during pregnancy in women who have not experienced asthma symptoms since childhood.
Warning signs to watch for
Signs that your asthma may be getting worse include:
If you have these symptoms, speak to your doctor or asthma specialist, who will advise you on the best treatment.
Signs of a severe asthma attack include:
If you experience any of the signs of a severe asthma attack, dial 111 and ask for an ambulance.
When asthma is well controlled during pregnancy, you will generally have a normal pregnancy will little or no increased risk of harm to you or your developing baby.
If your asthma is not controlled during pregnancy, it can cause possible harm to you and your baby. If you're having trouble breathing, your baby might not get enough oxygen.
Any medication you take during pregnancy can affect your baby, but most asthma treatments are safe to use when you are pregnant. Medical experts advise that it is far safer to manage your asthma with medicine than it is to leave asthma untreated during pregnancy. Keep taking your asthma medication as normal unless instructed to do otherwise by your doctor.
There are many things you can do to help reduce the severity and frequency (how often) of your asthma symptoms, such as:
Read more about what you can do to manage your asthma.
Most women do not get severe asthma symptoms during labour and delivery. Some women may be advised to have continuous monitoring of the foetus during labour and delivery. If you are taking asthma medication, continue doing so during labor and delivery. During labour and delivery you have the same choice of pain medication as any woman.
Asthma and pregnancy NHS Choices