Asthma in pregnancy: inhalers, attacks and labour

There is no single pattern. Some women notice fewer symptoms, others have more cough, wheeze or breathlessness, and for some nothing changes. Hormonal shifts, a growing abdomen pressing on the diaphragm and colds all play a part, and the NHS adds that acid reflux, which is common in pregnancy, can make asthma symptoms worse.

Because breathlessness is also a normal feature of pregnancy, it can be hard to tell the two apart. A useful clue is wheeze, night-time cough, chest tightness or needing your reliever inhaler more often than before. Peak flow readings, if you use them, give a more objective view.

The NHS states that if asthma is well controlled there is little to no risk to you or your baby, and that stopping treatment can lead to worse outcomes. The reasoning is straightforward: during an attack the amount of oxygen available to the baby can fall, so the aim is to prevent attacks rather than to minimise drug exposure.

Many women stop their preventer inhaler because they are worried about the baby, then find symptoms return. If you are uneasy about any medicine, raise it with your GP, asthma nurse, pharmacist or midwife. The NHS says to check medicines with a health professional and not to stop prescribed ones without approval.

The NHS asthma page recommends an annual review to check inhaler technique and keep your personal asthma action plan up to date, and notes that pregnant women should tell their healthcare provider so asthma can be managed properly. A review early in pregnancy, and another if symptoms change, makes sense.

• Carry your reliever inhaler at all times, and check it has not run out or expired.

• Keep taking any preventer inhaler as prescribed.

• Avoid known triggers such as smoke, pollution or allergens, and stop smoking if you smoke.

• Ask whether you are due a flu vaccination, since infections can trigger asthma and are more serious in pregnancy.

• Ask your midwife to record that you have asthma so it is known on the maternity unit.

The NHS describes sitting upright, staying calm and taking one puff of the reliever inhaler every 30 to 60 seconds, up to a maximum of 10 puffs. Call 999 if symptoms do not improve after the maximum dose, if they get worse at any time, or if you do not have an inhaler to hand.

Contact your GP or NHS 111 sooner if you are using more reliever than usual or have shortness of breath or chest tightness. In pregnancy you should also tell your maternity unit about a significant attack, because the baby's wellbeing may be checked afterwards.

The NHS says asthma attacks during labour are very rare and that using your reliever inhaler in labour is safe. Tell the staff you have asthma and bring your inhalers to hospital. Mention any allergies, including to medicines, because those and asthma often occur together.

Your midwife and obstetrician will take asthma into account when choosing pain relief and medicines that could trigger wheeze. Most women with asthma give birth in the same way as those without.

The NHS advises that it is safe to continue any asthma treatment while breastfeeding and that keeping asthma controlled remains important after birth. Sleep deprivation, new infections and changing routines can unsettle asthma, so keep your action plan close and arrange a review with your GP or asthma nurse in the weeks after delivery.

If your child later develops wheeze, you can discuss it with your health visitor or GP. Our guides to asthma in adults and children cover these topics separately.