Breastfeeding Guidance for Medical Physics Investigations

This information leaflet is to help you prepare before and after your medical physics procedure if you are breastfeeding.


Medical physics investigations involve the administration of a radioactive tracer (radiopharmaceutical). Depending on the test you are coming for this may be given to you as an injection, swallowed or breathed in as a gas.

Some of these radiopharmaceuticals are excreted by your body in breastmilk and it is therefore important that we prevent them passing on to your baby during feeding.

If you have received one of these radiopharmaceuticals then you will not be able to breastfeed for a set period of time after the test. It is therefore important that you follow the instructions below.

Before coming for your test

It is important that you make alternative arrangements for a short period, to feed your baby after your test. You may choose to express breastmilk and store it for use during the restriction period. Alternatively, you can feed your baby using formula during the restriction period.

We recommend that you feed your baby naturally just before attending for the test.

After the test

After receiving your radiopharmaceutical administration it is important that you do not allow your baby to breastfeed until the restriction period has passed.

Three to four hours after the test you should express your breastmilk as fully as possible and throw it away. You should continue to do this as necessary throughout the restriction period.

Your baby should be fed during the restriction period by an alternative method, either using the previously banked breastmilk or formula.

At the end of the restriction period

Once the restriction period has ended you can return to feeding your baby as normal.


Restriction Periods

There are different restriction periods for different tests. The table below can be used to see how long you will need to stop breastfeeding for.

InvestigationRestriction Period
Lung ScanUp to 20 hours
Parathyroid Scan30 hours
Thyroid Scan30 hours
Gastric Emptying13 hours
SeHCAT4 hours
Cardiac MIBG25 hours

If you are attending for any other medical physics investigation then there are no restrictions to breastfeeding. If you are in any doubt or have any questions please contact the medical physics department, details can be found at the end of the leaflet.

Close contact with your baby

The majority of medical physics investigations do not require you to restrict contact with your baby. However, a small number do. If you are attending for a parathyroid scan or a heart scan please contact the medical physics department for further advice.

Contact numbers for further advice

Superintendent Radiographer/Clinical Technologists
Medical Physics
Tel: (0191) 445 2710
Monday to Friday 8:30am to 4:30pm

Physicist/Head of Medical Physics
Tel: 0191 445 2476 or 0191 445 5516
Monday to Friday 9am to 4:30pm