Low dose aspirin (150mg) in pregnancy

You have been given this information leaflet as you have been advised to take low dose aspirin, 150mg once a day from 12 to 36 weeks of your pregnancy.

What is aspirin?

Aspirin is known as an NSAID (a non-steroidal anti-inflammatory drug). Aspirin is often used to treat pain, fever, inflammation, or prevent clot formation.

There is evidence that taking low dose aspirin once a day can help increase the function and blood flow of your placenta (afterbirth), which provides your baby with oxygen and nutrients during your pregnancy to help them grow.

Why have I been advised to take aspirin?

Not everyone is recommended to take aspirin in pregnancy. You have been advised to take a low dose of aspirin during your pregnancy to reduce the risk of:

• developing hypertension (high blood pressure) and pre-eclampsia (high blood pressure and protein in your urine)

• giving birth to your baby prematurely (before 37 weeks)

• your baby being smaller than expected.

Your midwife or obstetrician (a doctor who specialises in the care of pregnant women) may recommend that you take low dose aspirin to reduce the risk of hypertension (high blood pressure) if one of the following apply to you.

• You had hypertension (high blood pressure) during a previous pregnancy.

• You have chronic kidney disease.

• You have an auto-immune disease (for example, lupus or antiphospholipid syndrome).

• You have Type 1 or 2 diabetes.

• You have chronic hypertension (high blood pressure before pregnancy).

• You have previously given birth to a baby who was smaller than expected.

• You have low Pregnancy Associated Plasma Protein (PAPP-A) screening blood test.

• You are aged 40 years or older.

Low dose aspirin may also be recommended if two or more of the following apply to you.

• This is your first pregnancy.

• There are more than 10 years between this pregnancy and the birth of your last baby.

• Your BMI is 35 or more at your booking appointment.

• There is a family history of pre-eclampsia in a first degree relative (parent, full sibling, or child).

• This is a multiple pregnancy (for example, twins or triplets)

You may also be advised to take low dose aspirin if you have a slightly higher chance of having a baby which may be smaller than expected. Or there were any concerns about how your placenta was working in a previous pregnancy; this will be discussed with you.

How and when do I take aspirin?

You should take 150mg (2 x 75mg tablets) once a day from 12 weeks, until 36 weeks of your pregnancy. It is best to take in the evening either with or just after food.

Please do not worry if you forget to take a tablet, just take one when you remember, however make sure you only take 150mg once a day.

If you think you may be in labour, you can stop taking your aspirin until this is confirmed. It will not increase your risk of bleeding during your labour.

Is low dose aspirin safe to take in pregnancy?

Low dose aspirin is not known to be harmful to you or your baby during pregnancy. In fact it is known to reduce the risk of harm by reducing the risk of high blood pressure, pre-eclampsia, smaller babies, and stillbirth.

However, aspirin can affect (and be affected by) other medications, including over-the-counter medicines and herbal remedies. Please discuss any other medications you are taking with your midwife, GP, or obstetrician.

What are the possible side effects?

• Taking low dose aspirin can cause mild indigestion. If you take your aspirin either with or just after food, it will be less likely to upset your stomach. Avoid taking aspirin on an empty stomach. If you also take indigestion remedies, take them at least two hours before or after you take your aspirin.

• There is no evidence to suggest low dose aspirin causes any increase in bleeding during pregnancy or at the time of birth.

If you have any questions or concerns about taking low dose aspirin, please speak to your obstetrician, GP, or midwife.

What if I have any allergies?

Please tell your obstetrician, midwife, or GP if you are allergic to aspirin (or other NSAIDS), or you have severe asthma, chronic kidney problems, stomach ulcers, or have been previously advised not to take aspirin or other NSAIDs.

As with any medicine, you should ask for urgent medical help if you have serious side effects, such as wheezing, swelling of the lips, face or body, rashes, or other signs of an allergic reaction.

What can I do to help myself and my baby?

If you smoke it is very important that you stop, as it can affect placental (afterbirth) function and your baby’s growth. If you need support to stop smoking, please contact One You Kent on 0300 123 1220, or email.

Further information

If you would like more information about taking low dose aspirin in pregnancy, your midwife or obstetrician will be happy to answer your questions and advise you.

• Best use of medicines in pregnancy (BUMPS)

• NHS: low dose aspirin

Important information

The information in this leaflet is for guidance purposes only and is not provided to replace professional clinical advice from a qualified practitioner.

This leaflet has been produced with grateful acknowledgement to East Sussex Healthcare NHS Trust.