Medicines in pregnancy, children and lactation
There is a wealth of information for us to use when considering medications prescribed for use in pregnancy, while breastfeeding and with children.
Prescribing
There is a wealth of information for us to use when considering medications prescribed for use in pregnancy, while breastfeeding and with children. It isn’t always easy to find this information in one place so we have put together guidance and links for you to use when making appropriate decisions with your patients.
The information and links provided are for guidance, clinical decisions remain the responsibility of the practitioner; the intention is to help prescribers find evidence based information and does not replace input from appropriate professionals or constitute medical advice for individual patients.
Please contact sam.morris2@nhs.net with any suggested edits, or any additional resources you feel would be useful to be shared as these documents will be reviewed when appropriate.
Pregnancy Planning & Staying Well in Pregnancy & Beyond
Use of medicines in pregnancy and breastfeeding Guidance from the MHRA January 2021, updated August 2022
Please see individual formulary pages on medicines used in pregnancy and breastfeeding linked above for resources.
The BNF (British national formulary) should only be used as a guide as it does not contain quantitative data on which to base individual decisions, specialist resources including UKTIS, UKDILAS and the SPS should be used for evidence based information.
NICE PH11 Maternal and child nutrition has been replaced by NICE NG247 | Maternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to 5 years
NICE NG194 Postnatal care page 27 to see the role of the healthcare professional supporting breastfeeding
The Safer Medicines in Pregnancy and Breastfeeding Consortium brings together 16 leading organisations under a common pledge to meet the information needs of pregnant and breastfeeding women and healthcare professionals, through accessible, clear and consistent advice.
The UK Preconception Partnership Early- and Mid-Career Researchers (EMCR) Network and the Faculty of Public Health’s Special Interest Group on Health of Women and Girls have launched a new Preconception care toolkit, which supports action to reduce inequalities in preconception health.
The toolkit is intended for professionals responsible for commissioning health or health improvement services. This includes (but is not limited to) teams within Integrated Care Boards (ICBs), Local Authorities and healthcare providers. The toolkit includes population data indicators, guidance and evidence summaries, and case studies of service models.
The toolkit aims to support professionals to:
- Access the data indicators that enable the preconception health of a population to be assessed and monitored over time.
- Access key guidance documents and summaries of the latest evidence, specifically related to the commissioning and implementation of interventions to improve preconception health.
- Learn about different approaches and models of preconception care in England, including how services have been designed to reduce inequalities in health outcomes.
Preconception Care Toolkit 2025
Since 2017, we have been building on the resources available for safe prescribing in pregnancy and lactation. In April 2023, Somerset started working on improving conversations for people taking regular medication who are of childbearing potential through the scorecard quality incentive workstream.
We have seen a 44% decrease in patients on a smart list of medications which are being monitored as part of the medicines management scorecard, seeing a change from 2,999 patients to 1,660 patients who are not on contraception, or counselled on the risks of their medication, a year later.
In April 2024, we have expanded this list of drugs to also include bempedoic acid, chlordiazepoxide and the type 2 diabetes medications. More information can be found on the Scorecard page.
The aim of this work is to change the culture around prescribing to people of childbearing potential, to make every contact count, and to ensure people know where they can go if they plan a pregnancy, or become pregnant. We do not want access to treatment to be restricted, but for access to safe prescribing to increase.
More information can be found on the Medicines used in pregnancy - NHS Somerset ICB page for resources on safe prescribing in pregnancy, prevention including vitamins and daily supplements, as well as reducing the risk of pre-eclampsia in people at risk (via the use of low dose aspirin in suitable people.)
Consideration should be made to optimise medication for ongoing journeys, future pregnancies and being mindful of suitability of medication during lactation as well as pregnancy to avoid unnecessary repeated changes to medication regimes when compatible choices could be made where clinically suitable in the first instance.
Many more medications are compatible in lactation than in pregnancy, however, there will be some instances where a medication choice may cause difficulties for a parent to achieve a full milk supply, for instance aripiprazole is known to dramatically reduce prolactin levels, while it is not "unsafe" to use during pregnancy or breastfeeding, the impact on establishing a full milk supply may be so profound that exclusive breastfeeding may be not possible- if this was the parents wish, they should be supported to maintain their health and wellbeing, as well as achieve their personal breastfeeding/ chestfeeding goals. For more information on prescribing in lactation you can access the Breastfeeding and medicines - NHS Somerset ICB page where there are resources on safe prescribing, as well as training materials on how medications enter the milk, and how lactogenesis works.
Mums and birthing people have often been in charge of ensuring their medications are compatible with pregnancy, there are a number of medications which are known to not be compatible with pregnancy, some known to be teratogenic which have Pregnancy Prevention Plans in place, and other medications which currently lack evidence for safety in pregnancy.
More information can be found on the Medication Safety - NHS Somerset ICB page.
Paternal Exposure
It's important to understand that fathers, non-gestational parents and those considering sperm donation also need to consider if their medication is safe to take prior to conception/ sperm donation.
There is not as much information available on paternal medicine exposure, more information can be found on the UK Teratology Information Service as well as looking at individual drug Summary of Product Characteristics.
A non-exhaustive list for further resources on medications with teratogenic potential from paternal exposure include:
- Azathioprine or mercaptopurine
- chlordiazepoxide
- finasteride
- methotrexate
- sodium valproate/ valproic acid
The latest MHRA warning on Valproate Use in Men September 2024, outlines measures healthcare professionals should take to support their patients to make informed decisions when starting a family. Advice for healthcare professionals:
- inform male patients (of any age) who may father children of the possible risk at initiation of valproate or at their next regular treatment review – this counselling should be given irrespective of the indication for valproate and also after intravenous use of valproate
- as a precaution, recommend that male patients use effective contraception (condoms, plus contraception used by the female sexual partner) throughout the valproate treatment period and for 3 months after stopping valproate, to allow for one completed sperm cycle not exposed to valproate
- at the next regular treatment review, discuss with men on oral valproate treatment whether they are planning a family in the next year and if they are, refer to a specialist to discuss alternative treatment options
- if a female patient reports they are pregnant or planning a pregnancy with a man on valproate (including those undergoing IVF), refer for prenatal counselling
- advise men not to donate sperm during valproate treatment and for 3 months after stopping valproate
- report any suspected adverse drug reactions associated with valproate on a Yellow Card
Pregnancy Prevention Programmes and MHRA warnings for medicines to be avoided in pregnancy
More information can be found on the Medication Safety - NHS Somerset ICB page where we have more information on:
Other drugs subject to a Pregnancy Prevention Programme include:
- thalidomide
- lenalidomide
- pomalidomide
- vismodegib
The latest Drug Safety Updates can be accessed on the MHRA website: Drug Safety Update - GOV.UK (www.gov.uk)
NEW NHS Referral link available for patients to self-refer into maternity services: Refer yourself for NHS pregnancy care - NHS
Somerset Referrals available for Somerset Foundation Trust
Poster Text:
Positive Test? Book Before 10 Weeks!
Search 'Somerset Foundation Trust Maternity' or Scan the QR code
https://www.badgernotes.net/SelfReferral/CareLocation/somerset
Your first midwife appointment (also called the booking appointment) should happen before you're 10 weeks pregnant. This is because you'll be offered some tests that can only be done in early pregnancy. However, you will be well cared for whenever you tell us you are pregnant, it's never too late!
The MHRA have published guidance on the use of: GLP-1 medicines for weight loss and diabetes: what you need to know - GOV.UK
People of childbearing potential should use effective contraception to take steps to avoid pregnancy.
The alert also advises that these medications should not be used during breastfeeding. If your patient has a clinical need for these medications while breastfeeding, expert knowledge should be sought with an individual risk- benefit decision made including the benefits of continued breastfeeding for your patient and their child on a shared-decision making basis.
The Summary of Product Characteristics for Mounjaro has now been updated to include information on use while breastfeeding, it states:
Breast‑feeding
In a study of 11 women, the concentration of tirzepatide in breastmilk was found to be undetectable to very low (<10 ng/ml) compared to plasma concentrations following a single 5 mg dose. As tirzepatide is an amino acid sequence, any low amount present in breastmilk is expected to be degraded and not orally absorbed as intact drug by the breastfed infant. It is not known whether the reduced maternal food intake caused by tirzepatide affects composition or nutrient content of the breast milk. Overall, tirzepatide could be considered for use during breast-feeding.
Mounjaro KwikPen 10mg solution for injection in pre-filled pen - Summary of Product Characteristics (SmPC) - (emc) | 15484 09 April 2026
Information on breastfeeding can be found: Diabetes and Breastfeeding - The Breastfeeding Network and Breastfeeding Medicines Advice service – SPS - Specialist Pharmacy Service – The first stop for professional medicines advice
Information on contraception can be found on the Faculty of Sexual and Reproductive Healthcare Patient Information GLP-1 agonists and contraception FSRH Leaflet
For information on pregnancy and medications, information is available from UKTIS – Evidence-based safety information about medication, vaccine, chemical and radiological exposures in pregnancy for healthcare professionals and Bumps - Best use of medicines in pregnancy for patients.
Metformin and insulin remain the preferred treatment choices in diabetes during pregnancy and breastfeeding.
