Aspirin for pain

Date: May 2025, Version 1.0

Quick read

Use of aspirin to treat pain (at doses of 300 mg to 4 g per day) during pregnancy is not advised unless prescribed by a doctor, especially if you are 20 or more weeks pregnant.

Low dose aspirin (at doses of 75 mg to 150 mg per day) to prevent pre-eclampsia and heart problems is safe during pregnancy. For more information, see the Bump leaflet on Low dose aspirin.

What is it?

Aspirin to treat pain and a high temperature usually comes as 300 mg tablets (Disprin®, Nu-Seals®). The recommended dose is two to three tablets every four to six hours to a maximum of around 13 tablets (4 grams) per day. Aspirin can be bought from a pharmacy or may be prescribed by a doctor.

Benefits

What are the benefits of taking aspirin to treat pain in pregnancy?

Use of aspirin to treat pain during pregnancy is not advised unless prescribed by a doctor, especially if you are 20 or more weeks pregnant. Taking aspirin before week 20 of pregnancy is unlikely to harm your baby.

Risks

Are there any risks of taking aspirin to treat pain in pregnancy?

Taking aspirin at doses to treat pain after week 20 of pregnancy can cause complications, some of which might be severe, such as:

• Reduced amniotic fluid around the baby – this can affect the baby’s lung and kidney development.

• Early closure of a blood vessel in the lungs (called the ductus arteriosus) that needs to stay open while the baby is in the womb for correct blood circulation. This can also lead to a serious lung condition in newborn babies called persistent pulmonary hypertension of the newborn (PPHN).

If you have taken aspirin for pain relief after week 20 of pregnancy, especially if you have taken several doses, please stop taking aspirin and speak to your doctor or midwife as soon as possible. Your obstetrician might want to check the baby and amniotic fluid levels by ultrasound scan. Effects on the unborn baby often improve once aspirin is stopped.

Alternatives

Are there any alternatives to taking aspirin to treat pain in pregnancy?

Yes. Paracetamol is usually recommended to control pain or fever during pregnancy. If paracetamol does not control your pain, you can ask your doctor for advice.

No treatment

What if I prefer not to take pain relief during pregnancy?

If pain is affecting your quality of life, it is important to get the right treatment so that you remain well. Your doctor will help you decide what is best for you and your baby and will only prescribe medicines when necessary.

Will my baby need extra monitoring during pregnancy?

Women in the UK will be offered a detailed scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Taking aspirin before 20 weeks of pregnancy would not normally require extra monitoring of your baby.

Women who have taken aspirin after 20 weeks of pregnancy might be offered a detailed scan to check the baby, depending on the exact stage of pregnancy, the amount of aspirin taken and the length of aspirin treatment.

Are there any risks to my baby if the father has taken aspirin?

We do not expect any increased risk to your baby if the father takes aspirin.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet, please discuss them with your healthcare provider. They can access more detailed medical and scientific information from www.uktis.org.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.