Medicines Healthcare Products Regulatory Agency
1. Medicines in pregnancy
Women may sometimes need to take medicines to protect their own health and the health of their baby during pregnancy.
Advice for patients
- If you are pregnant or planning a pregnancy and you need to take a medicine, speak to your doctor, pharmacist, or midwife because some medicines may affect the babys development. They can advise on the risks and benefits for you and the baby to help you decide what to do.
- If you have a chronic or recurring condition that requires long-term treatment, it is especially important to ask your doctor whether any changes are needed to your medicines.
- Do not stop taking prescribed medicines without talking to your doctor. The benefits of continuing your medication may be greater than any risks.
Further information is available from the following websites:
For patients and their families
For healthcare professionals
Medicines to avoid during pregnancy
Some medicines are known to be harmful in pregnancy. They may affect the development of the baby or mean the baby is more likely to be born with a disability.
Medicines may especially affect the baby during early development. This occurs in the first trimester which is 13 weeks since a womans last period. During this time a woman may not know she is pregnant.
When using any medicine that is known to be harmful in pregnancy:
- a woman should be advised of the risks to the baby if she were to become pregnant. She should be encouraged to use effective contraception throughout treatment. Contraception can prevent unintended exposure of a baby to a medicine during pregnancy.
- if a woman becomes or wishes to become pregnant, she should be offered information about the risks and benefits to her and her pregnancy of continuing treatment, of moving to an alternative treatment, or of stopping treatment altogether. The risks to the baby of exposure before a woman knew she was pregnant should be discussed.
- women should not stop using prescribed medication without seeking specialist advice.
Information about whether a medicine must be avoided during pregnancy is available in the patient leaflet that accompanies a medicine.
Our Drug Safety Update gives information for healthcare professionals on safety issues for medicines in pregnancy.
Contraception
If a woman is taking a medicine that is known to be harmful in pregnancy, she should be advised to avoid pregnancy during treatment. This involves using the most effective contraceptive method for her personal circumstances. A doctor, family planning nurse or clinic can advise on the most effective contraceptive methods. This includes the advantages and risks with each method.
Contraceptive methods do sometimes fail and unplanned pregnancies do occur. Performing a pregnancy test before each prescription is one way to avoid unintended exposure to a medicine that may be harmful.
See our guidance for healthcare professionals on frequency of pregnancy testing before and during treatment, depending on the chosen contraceptive method.
Pregnancy Prevention Programmes (PPP)
For some of the most harmful medicines, and where there is a high risk of unintended exposures, specific requirements may be in place to underline the need to avoid use in pregnancy.
A Pregnancy Prevention Programmes is a formal agreement between the patient and their doctor. It makes sure the patient understands the risks to the baby and knows how they should avoid becoming pregnant while on that medicine.
Examples include:
- sodium valproate
- oral retinoid medicines (including isotretinoin)
- thalidomide, lenalidomide, and pomalidomide
- vismodegib
2. Medicines in breastfeeding
Breastfeeding has long-term health benefits for both the mother and her baby.
Some medicines can pass from women through breastmilk to their baby. Only small amounts of the medicine usually reach the baby and most medicines can be used while breastfeeding. For some medicines, this may mean the baby should be monitored more often to make sure they are not harmed by the medicine whilst they are breastfed.
Advice for patients
- If you regularly take a medicine or have taken one during the late stages of your pregnancy, it is best to plan ahead. Talk to your doctor, nurse, or midwife about your breastfeeding options.
- Do not stop taking prescribed medicines without talking to your doctor.
- If you need to take a medicine for the first time, talk to your doctor, nurse, or midwife about how you can safely breastfeed your baby.
Information about when a medicine must be avoided whilst breastfeeding is available in the patient leaflet that accompanies a medicine.
Further information on breastfeeding and on use of medicines during breastfeeding is available from the following websites:
For patients:
For healthcare professionals:
3. Report a side effect of a medicine during pregnancy or breastfeeding
We work with medicine manufacturers to increase knowledge about the use of medicines during pregnancy and breastfeeding. However, there are still gaps in how much we know about their effects.
Reporting any side effects during pregnancy and breastfeeding, including any suspected miscarriage or harm to the baby, helps to increase the information available to everyone about the safety of medicines.
How and why to report an adverse reaction
- Drug Safety Update article explains about Yellow Card reports for pregnancy
- Report side effects via the Yellow Card scheme website or via the Yellow Card App via iTunes Yellow Card for iOS devices or via PlayStore Yellow Card for Android devices
4. Additional resources for clinicians and researchers
Importance of pharmacokinetic data in pregnancy and lactation
The level of a medicine in the blood depends on its pharmacokinetics (ie the kinetics of drug movement in the body). This describes how quickly a medicine moves into (absorption), within (distribution) and leaves (elimination) the body.
Changes in a womans body during pregnancy can change how quickly a medicine is distributed and eliminated from her body, which can affect how well the medicine works. By using pharmacokinetic (PK) data of changes in blood levels of the medicine during pregnancy, it is possible to estimate whether dose changes are needed to maintain the mothers and/or her babys health during pregnancy.
Our PK activities
We run a