Display Patient Information Leafelts

Prophylactic Clexane

Date issued: June 2020

For review: June 2022

Ref: F-47/Maternity/LR/Prophylactic Clexane v2

PDF : Prophylactic Clexane [pdf] 146KB

Why have you been prescribed clexane?

When you are pregnant your blood becomes more sticky and this means it can clot more easily. If you have other risk factors such as being a smoker, are overweight , previous family history of blood clots or have had a clot yourself  then you might be at risk of developing a clot in your leg (deep vein thrombosis or DVT) or in your lung (pulmonary embolism or PE). You are being advised to have clexane injections to reduce the risk of a clot forming in this pregnancy. This is known as prophylactic clexane.

Clexane (also known as enoxaparin) is a type of medicine called a low molecular weight heparin (LMWH). It is an injection which thins your blood and reduces the risk of developing blood clots (thrombosis). If you have developed a clot in this pregnancy it reduces the risk of you developing more.

Your doctors have assessed you and you have been advised to take clexane before and possibly after your baby is born. This is because the risk of developing the clot starts early in pregnancy and is highest after the baby is born.

It will prescribed by a doctor, and is always given by injection under the skin (subcutaneous). It is usually given once, sometimes twice a day.

How often and what dosage of the medication will be decided by the doctors depending on the risks that each lady has. Some ladies will then need to attend for extra blood tests in order to ensure that the amount given is correct.

So please remember that it is very important to attend for these appointments for all the blood tests.

You must complete the course of clexane even if you are discharged from the hospital.

Signs and symptoms to look out for

  • Pain, swelling and tenderness in your calf and /or thigh may be a sign of a deep vein thrombosis.

  • Chest pain, breathlessness, coughing blood and /or collapse maybe signs of pulmonary embolism.


Instructions on injecting yourself with clexane

Make sure you take the clexane at the same time every day. If you need to have an injection twice a day then give the first dose in the morning and second dose 12 hours later.

1) Wash your hands and make sure the area that you will inject is clean before you start 

Sit or lie in a comfortable position so you are relaxed. Make sure you can see the place you are going to inject. A lounge chair, recliner, or bed propped up with pillows is ideal. Have the sharps box and clean tissues or cotton wool within reach.

Decide where you are going to inject the medicine. Change the place where you inject each time to help prevent bruising.

Choice of sites to inject

Clexane should be injected just under the skin.

Remember: Do not inject yourself within 5 centimetres of your belly button or around existing scars or bruises. Change the place where you inject between the left and right sides of your stomach; depending on the area you were last injected.

2) Open the pack and remove the syringe. Carefully pull off the needle cap from the clexane syringe. Throw away the cap. The syringe is pre-filled and ready to use. Make sure the syringes are kept in a safe place at room temperature.

Do not press on the plunger before injecting yourself to get rid of air bubbles. This can lead to a loss of the medicine. Once you have removed the cap, do not allow the needle to touch anything. This is to make sure the needle stays clean (sterile).

Hold the syringe in the hand you write with (like a pencil) and with your other hand, gently pinch the cleaned area of your abdomen between your forefinger and thumb to make a fold in the skin

3) Hold the syringe so that the needle is pointing downwards (vertically at a 90° angle).To do this pinch a fold of skin between the thumb and fingers of one hand. 

Insert the full length of the needle into the skin fold.

Press down slowly on the plunger with your finger. This will send the medication into the fatty tissue of the


4)  Remove the needle by pulling it straight out. A protective sleeve will automatically cover the needle. You can now let go of the skin fold.

Note: the safety system allowing release of the protective sleeve can only be activated when the syringe has been emptied by pressing the plunger all the way down.

To avoid bruising, do not rub the injection site after you have injected yourself.

Drop the used syringe with its protective sleeve into the sharps bin provided. Close the container lid and place the container out of reach of children.

When the container is full, give it to your doctor or the hospital for disposal. Do not put it in the household rubbish.


Side effects of clexane

Clexane may have some side effects. The most common side effects are swelling, bruising and/or an occasional droplet of blood at the injection site after you have taken out the needle.

Rarely you may have a red and raised area that does not resolve. If you have any concerns please contact Day Assessment for review.

It is already more common to have nose bleeds in pregnancy but avoid blowing nose forcefully to reduce the risk of this.

If a child accidentally injects or swallows clexane, take them to a hospital Emergency Department straight away.

What will I have to do and where do I need to go if I need blood tests to check the level of clexane?

You need to have bloods taken as close to 3 hours after you have taken clexane as possible.

The blood tests are taken on Day Assessment Unit on level 6, Lancaster Suite and are usually done on a Wednesday or a Thursday morning.

You will be contacted after the bloods have been processed and the results reviewed by the haematologist consultant.

Is it safe to take clexane during pregnancy?

Yes.  The LMWH does not cross the placenta to the baby.  However if you start it in pregnancy you may need to be seen in the antenatal clinic to discuss when to stop the clexane prior to delivery.

Is it safe to breast feed when taking clexane?

Yes.  Only a very small amount of clexane is secreted in the breast milk.  This is so small that the baby will not be affected.

Can I travel when I am taking clexane?

If you need to travel by plane or for a long distance by car or other mode of transport then make sure that you drink plenty of fluids and walk around for a few minutes every hour.  Also wear elasticated stockings throughout your journey.

Check you have enough injections for the time you are away and know where you can locally get medical attention if needed.  For most airlines you will need a letter from your doctor to explain that you need to take your injections on the plane.  You can check with airlines if you have any questions.

If you forget to use clexane

If you forget to give yourself a dose, have it as soon as you remember.  Do not give yourself a double dose on the same day (or triple dose if usually taken twice a day) to make up for a forgotten dose.  Keeping a diary will help to make sure you do not miss a dose

If you stop using clexane

It is important for you to keep having clexane injections until your doctor decides to stop them.  If you just stop, or keep missing doses, without having this advice, you could get a blood clot which can be very dangerous.

What do I do if I think I am going into labour?

A doctor will explain to you during your pregnancy when you need to stop the clexane . This discussion will be in the antenatal clinic.

  • If you are due for your next clexane injection and you are having regular painful contractions then do not take your injection.

  • If you are coming in for induction then leave out the dose for that day.

  • If you are having a caesarean then leave out the dose for that day.

    If you do go into labour shortly after having a clexane injection it can affect your choice of pain relief.  This is because an epidural or spinal anaesthesia cannot be given within 12 hours of having clexane.


After you have had your baby 

Some women may only need to start clexane injections after the baby has been born.  However others will have started in pregnancy and will need to continue using clexane after the baby is born as well.

The length of time that you would be required to continue the injections will be decided by the doctor this is because your risk of developing a clot is still increased at this time.

How to contact us

If you are concerned in anyway using clexane (LWMH) you can contact either your community midwife or GP or telephone:

Maternity Day Assessment Unit on 01752 763676 / 245212


Maternity Labour Line 01752 430200


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