(Date: February 2018. Version: 3)

This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by Public Health England on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

What is it?

Loperamide (Imodium®, Norimode®, Diah-limit®, Diocalm ultra®, Normaloe®, Diaquitte®, Diasorb®, Entrocalm loperamide®) is a medicine usually used to treat short episodes of diarrhoea. Loperamide may also be prescribed to treat long-term diarrhoea due, for example, to irritable bowel syndrome, or to help digestion in people who have had part of their intestine removed.

Is it safe to take loperamide in pregnancy?

At present, there is information on only around 750 babies of women who were treated with loperamide during pregnancy (see below). More pregnancies need to be studied to be able to say whether or not use of loperamide in pregnancy is safe. When deciding whether treatment with lopermaide in pregnancy is appropriate, it is therefore necessary for women and their doctors to weigh up the risks and benefits to both mother and baby of not taking a specific treatment against those of continuing the treatment. The outcome of this assessment will vary from person to person and will depend on the severity of the mother’s condition and the complications that could arise if her treatment is altered.

What if I have already taken loperamide during pregnancy?

If you have taken any medicines it is always a good idea to let your doctor know that you are pregnant so that you can decide together whether you still need the medicines that you are on and to make sure that you are taking the lowest dose that works.

Can taking loperamide in pregnancy cause birth defects in my baby?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects. There is mixed scientific evidence about whether taking loperamide during the first trimester of pregnancy may increase the chance of having a baby with a birth defect.

The chance of birth defects has been studies in only around 700 babies born to women taking loperamide in early pregnancy. Although one small study showed that women who took loperamide were no more likely to have a baby with a birth defect than women who didn’t, a second larger study found that birth defects in general were more common in babies of mothers who took loperamide in pregnancy. This study also found a possible link between loperamide use in early pregnancy and hypospadias (where the urethral opening is somewhere on the underside of the penis instead of at the tip).  Two studies that investigated the chance of heart defects produced mixed findings, with one finding that babies exposed in the womb to loperamide had an increased chance of heart defects compared to babies unexposed to loperamide, and the second finding that they did not.

It is currently unclear whether any increased chance of birth defects observed in some studies may be due to a direct action of loperamide itself or might be caused by nutrient imbalances or other features of the underlying conditions that loperamide is used to treat when used long-term. Well-designed studies of much larger numbers of pregnant women need to be carried out before we can say whether use of loperamide in early pregnancy increases the chance of birth defects in the baby.

Can taking loperamide in pregnancy cause miscarriage?

A very small study of 105 pregnant women taking loperamide showed no link with miscarriage. This result requires confirmation in much larger studies.

Can taking loperamide in pregnancy cause preterm birth, or my baby to be small at birth (low birth weight)?

Two studies of a total of around 750 pregnant women taking loperamide did not show that they had a higher chance of having a pre term birth (before 37 weeks), or a low birth weight baby (weighing less than 2,500g at birth). However, information from larger numbers of women is required before firm conclusions can be drawn.

Can taking loperamide in pregnancy cause stillbirth?

No studies have investigated the chance of stillbirth following use of loperamide in pregnancy.

Can taking loperamide in pregnancy cause learning or behavioural problems in the child?

A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.

No studies have investigated learning and behaviour in children who were exposed in the womb to loperamide.

Will my baby need extra monitoring during pregnancy?

Taking loperamide during pregnancy is not expected to cause any problems that would require extra monitoring of your baby. If you have an underlying illness that causes severe long-term diarrhoea, your doctor may wish to monitor your baby’s growth in the womb more closely.

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

We would not expect any increased risk to your baby if the father took loperamide before or around the time you became pregnant.

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 health care provider. They can access more detailed medical and scientific information from www.uktis.org.  

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General information 

Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks.  They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.

Medicines use in pregnancy

Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby.  There are, however, some medicines that can harm a baby’s normal development.  How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.

If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.

When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.   

Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.



Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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