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FACTSHEET

Diabetes and Breastfeeding

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This factsheet is intended to provide access to relevant evidence-based information. The national guidelines, research, data, pharmacokinetic properties and links shared are taken from various reference sources, they were checked at the time of publication for appropriateness and were in date. These are provided where we believe the information may be useful but we do not take any responsibility for their content. The factsheet is provided to empower users to make an informed decision about their treatment; but it does not constitute medical advice and cannot replace medical assessment, diagnosis, treatment or follow up from appropriately trained healthcare professionals with relevant competence.

The Breastfeeding Network factsheets will be reviewed on an ongoing basis, usually within three years or sooner where major clinical updates or evidence are published. No responsibility can be taken by the Breastfeeding Network or contributing authors for the way in which the information is used.

If you have any questions about this information, you can contact the Drugs in Breastmilk team through their Facebook page or on druginformation@breastfeedingnetwork.org.uk.

You can breastfeed as usual if you are using Insulin in Type 1 and Type 2 diabetes, and metformin in Type 2 Diabetes.

You may be able to use some other medications for diabetes whilst breastfeeding, with caution. See details below.

Breastfeeding reduces the risk of your baby developing diabetes.

Contents

Introduction

What is Diabetes?

Diabetes mellitus is a condition which affects your body’s ability to control your blood sugar levels, leading to blood sugar levels being too high. There are three main types of diabetes covered in this factsheet.

Diabetes is known as a blood sugar condition, but it isn’t just about sugar levels. Diabetes also affects your heart health, kidneys, eyes, nerves and circulation.

Type 1 diabetes is a lifelong condition where your body cannot release insulin or releases far too little insulin to maintain safe blood sugar levels. It is usually caused by your body’s immune system destroying insulin-making cells (known as an autoimmune condition). You can read more about Type 1 diabetes on the NHS website Type 1 diabetes.

Type 2 diabetes happens when your body doesn’t release enough insulin for your body’s demands, or your body becomes resistant to insulin so doesn’t react to it properly. You can read more about Type 2 diabetes on the NHS website Type 2 diabetes.

Gestational diabetes can develop during pregnancy and usually resolves when you give birth. Treatment will be tailored to your pregnancy and how well your blood glucose levels are controlled. If you are breastfeeding with gestational diabetes, you can see below for information on the safety of breastfeeding and medicines used to lower your blood glucose levels.  You can read more about gestational diabetes on the NHS website Gestational diabetes.

Diabetes in Pregnancy

If you have diabetes in pregnancy, you will be offered low-dose aspirin during your pregnancy to reduce your risk of pre-eclampsia. For information on low dose aspirin (75-150mg) while breastfeeding please see here. You will also be offered high dose folic acid (5mg folic acid once daily) while you are trying to conceive, and for the first 12 weeks of your pregnancy. You can continue to breastfeed as usual when taking folic acid.

Weight Loss Medicines

Some Type 2 diabetes medications are also used for weight loss. For weight loss only, they are available privately through online and in-person weight loss clinics, as well as NHS weight-loss services. National guidelines for NHS treatment with these medications are limited to set criteria. Private clinics may be able to offer these medicines to a wider group of people.

It’s important to consider the risks and benefits of these medicines carefully before choosing to use them, particularly if you access them though a private clinic where you may not have access to a dietician, or a dietician with expertise in breastfeeding. It is important that you are fully supported to ensure you are getting adequate nutrition to avoid negative impacts on your health and wellbeing. You can speak to your GP before deciding to use these medicines too.

Medications include:

GLP-1 therapy (glucagon-like peptide-1 receptor agonists) – Liraglutide as Saxenda® and Semaglutide as Wegovy®.

Dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 agonist – Tirzepatide as Mounjaro®.

Concerns have been raised about adequate nutrient content of breastmilk while taking GLP-1 agonists for weight loss. The evidence for this is poor and expert opinion suggests as long as you have enough weight to lose, that your milk should be unaffected (Hale). You are advised to take a multivitamin with sufficient vitamin D and to ensure you consume enough calories and protein to meet your needs while breastfeeding. This could be a challenge if your appetite is severely affected. Dr. Thomas Hale discusses this in more detail in his article Weight Loss in Lactation from the InfantRisk Centre. Evidence in this area is limited. A decision on whether these treatments are right for you and your child will need to be made in partnership with your healthcare professional, based on a benefit and risk discussion for you individually.

You will be able to find information on these medications below in the relevant sections in the factsheet.

For more information, you can contact the Breastfeeding Network Drugs in Breastmilk team.

Symptoms of Diabetes

Symptoms of diabetes may develop slowly over a number of years, in the case of Type 2 diabetes, or come on very quickly in instances of Type 1 diabetes. Common symptoms which you may have experienced, or need to see your GP quickly about, include:

  • feeling very thirsty even if you are drinking more than usual.
  • needing to wee/ urinate more frequently than usual, particularly at night
  • feeling very tired
  • weight loss without trying to lose weight (more likely in type 1 diabetes)
  • itching around the genitals, or frequent episodes of thrush
  • blurred vision
  • fruity smelling breath
  • passing out

If your symptoms come on very quickly, or happen when you are unwell, you may need to seek urgent medical help. Follow your treatment plan and call 111 or 999 if you are concerned about your symptoms.

For further information see Diabetes UK – Know diabetes.

Lifestyle Measures to Maintain Health With Diabetes

Low or lower carbohydrate diets may be advised by your diabetes team. This involves reducing the amount of starchy food you eat, such as bread, pasta, pizza, rice and potatoes, in favour of a higher protein diet.

While breastfeeding, your treatment may need to be adjusted to meet your needs while you are using energy to make milk. You may need a lower dose of insulin or other treatments during this time compared to in pregnancy, or before you became pregnant. Your diabetes team will help you find the right dosing. If you’re struggling to maintain your sugars in your agreed range, you can contact your team for further help. It is important to keep your blood sugars well controlled while breastfeeding, to ensure you remain well, and to ensure your milk supply can fully establish in the early days.

Further resources for eating well and keeping healthy with diabetes include:

Type 2 diabetes – Food and keeping active – NHS

Diabetes UK: what is a healthy, balanced diet for diabetes?

Diabetes UK: eating out with diabetes

Diabetes UK: cooking for people with diabetes

Diabetes.co.uk: food, nutrition and recipes message board

Cardiovascular/ Heart Health

National guidelines on diabetes advise on preventative treatment to reduce the risk of cardiac events, known as primary prevention. Risks to consider include:

  • hypertension (high blood pressure) maintaining your blood pressure within safe levels
  • dyslipidaemia (high cholesterol) ensuring your cholesterol levels are kept within range
    • Cholesterol management, including being offered statins that lower your cholesterol levels, is considered for people with type 1 diabetes over the age of 40 years, or if you have had type 1 diabetes for longer than 10 years.
    • If you have type 2 diabetes, your heart risk will be calculated using a calculator called QRISK3.
  • smoking – stop, if possible
  • obesity and weight management
  • family history of premature cardiovascular disease in a first-degree relative (a parent or sibling experiencing cardiovascular disease before the age of 60 years).

You can read more about cardiovascular disease on the NHS website cardiovascular disease

National Guidelines for the Management of Diabetes

National guidelines- NICE guideline 28- Type 2 diabetes in adults: management has a visual summary of Type 2 diabetes treatment, which also contains a summary table of medicines, including some key benefits and side effects.

NICE guideline 17- Type 1 diabetes in adults: diagnosis and management discusses management of Type 1 diabetes.

These guidelines are written for healthcare professionals but may be useful to you when discussing your treatment with your healthcare professional.

Safe Bed Sharing with Diabetes

If you take medication which increases your risk of hypoglycaemia (low blood sugar), bed sharing with your baby will be less safe. For more information, see the NHS hypoglycaemia information page. For more information on safe bedsharing, you can find resources on the BASIS – Baby Sleep Information Source website

Treatments for Diabetes

Insulin

Insulin is the only treatment for controlling blood sugar levels in Type 1 diabetes. It may also be used in some people with Type 2 diabetes and gestational diabetes where other treatments are not effective.

Insulin is a natural hormone produced in the pancreas; this is known as endogenous insulin. Endogenous insulin is found in breastmilk in low levels. Insulin is also usually found in breastmilk in low levels when you take insulin as a treatment (this is known as exogenous insulin). Exogenous insulin in your milk will be destroyed in your infant’s gut, and therefore not absorbed. Insulin is not active if taken by mouth, this is why insulin is given by injection and not oral tablets.

If you are taking insulin while breastfeeding, you may need more input from your specialist team to find the right balance of carbohydrate intake and insulin dosing, particularly in the postpartum period when your milk production is increasing and you are recovering from pregnancy and birth.

If you are taking insulin while breastfeeding, your risk of hypoglycaemia is high. Careful monitoring is needed. Your diabetes team will support you with this. For information on safe bedsharing, you can visit the BASIS – Baby Sleep Information Source website.

You can use all types of insulin while breastfeeding. Precautionary monitoring of your baby is recommended for signs of hypoglycaemia, adequate feeding, not waking for feeds, and expected weight gain, but there have been no reports of side effects in children through breastfeeding. You can read more about insulin on the NHS Insulin webpage. You can read more about hypoglycaemia in babies on this NHS page.

Treatments for Type 2 diabetes

Biguanide Therapy

  • Metformin (various brands available, commonly prescribed by the drug name metformin)– Metformin works by increasing the body’s sensitivity to its natural insulin. This reduces your blood glucose levels.
  • Metformin is the first line treatment for type 2 diabetes, including if you are pregnant or breastfeeding.
  • If you need to take metformin while breastfeeding, you can continue to breastfeed as usual.
  • Precautionary monitoring of your baby is recommended for vomiting, diarrhoea, signs of hypoglycaemia, adequate feeding and expected weight gain. However there have been no reports of side effects in children through breastfeeding.
  • The risk of metformin causing you hypoglycaemia is low.
  • You can read more about metformin on the NHS website Pregnancy, breastfeeding and fertility while taking metformin

DPP-4 Inhibitor Therapy – known as gliptins (dipeptidyl peptidase-4 inhibitor)

Gliptins help your body to produce more insulin and reduce the amount of glucose released by your liver when it’s not needed. Their risk of causing you hypoglycaemia is low.

There is currently no information available on the use of gliptins while breastfeeding.

Alternatives may be preferred, especially if you are feeding a newborn, or premature infant.

Additional caution should be taken if you are feeding a baby whose sole or main source of nutrition is breastmilk (under 6 months or under 12 months of age respectively).

Gliptins are not compatible with pregnancy. If you are taking these medicines, you should discuss contraception, if needed, with your healthcare professional and talk to them before planning your next pregnancy so your treatment can be reviewed.

If you take a gliptin while breastfeeding, you should monitor your child for signs of hypoglycaemia, including: being sleepy, or drowsy, irritability, jitteriness, tremors, pallor (paler than usual), sweating, not settling, changes in feeding including poor feeding.

  • Alogliptin- (as own brand, Vipidia®)-
  • No information is available on the clinical use of alogliptin during breastfeeding.
  • Alogliptin stays in the body for a longer time than the other gliptins and is well absorbed when taken by mouth.
  • It is likely that alogliptin will pass into your breastmilk, based on how it acts in the body. However, we don’t know how much will pass into your milk.
  • Monitor your child for signs of hypoglycaemia.
  • Other gliptins may be preferred.
  • You can read more about alogliptin on the NHS website Pregnancy, breastfeeding and fertility while taking alogliptin
  • Linagliptin- (as Trajenta®)-
  • No information is available on the clinical use of linagliptin during breastfeeding.
  • Linagliptin is unlikely to pass into breastmilk in clinically significant amounts.
  • Monitor your child for signs of hypoglycaemia and changes in their nappy output.
  • If there is concern, monitoring your child’s blood glucose levels is advised whilst you are taking linagliptin.
  • You can read more about linagliptin on the NHS website Pregnancy, breastfeeding and fertility while taking linagliptin
  • Saxagliptin- (as Onglyza®)-
  • No information is available on the clinical use of saxagliptin during breastfeeding.
  • Saxagliptin stays in your body for less time than other gliptins and it doesn’t get into the body easily when taken by mouth, so it is unlikely to transfer to your child in significant amounts.
  • Monitor your child for signs of hypoglycaemia and rash. 
  • If there is concern, monitoring your child’s blood glucose levels is advised whilst you are taking saxagliptin.
  • You can read more about saxagliptin on the NHS website Pregnancy, breastfeeding and fertility while taking saxagliptin
  • Sitagliptin- (as own brand, Januvia®)
  • No information is available on the clinical use of sitagliptin during breastfeeding.
  • Sitagliptin stays in the body for less time than alogliptin, however it is expected to enter your milk in low amounts.
  • Monitor your child for signs of hypoglycaemia.
  • You can read more about sitagliptin on the NHS website Pregnancy, breastfeeding and fertility while taking sitagliptin

GLP-1 Agonist Therapy (glucagon-like peptide-1 receptor agonist)

GLP-1 agonists increase hormones called incretins. These help your body to produce more insulin and reduce the amount of glucose released by your liver when it’s not needed. They also reduce the speed that your stomach digests foods, slowing stomach emptying, which reduces appetite. Their risk for causing you hypoglycaemia is low.

GLP-1 agonists may reduce the effectiveness of oral contraceptives and other oral medication due to their impact on the digestive system. Read the patient information leaflet for more information.

GLP-1 agonists are not compatible with pregnancy. Manufacturers advise that you stop these medicines before you become pregnant, in some cases three months before a planned pregnancy. You will need to consider this when planning contraception and building your family in the future.

GLP-1 agonists may cause unpleasant side effects including dizziness, headache, indigestion or upset stomach, nausea, vomiting, diarrhoea and feeling jittery. Individual drugs may cause other side effects too. If these are severe, you may find it difficult to care for your baby without assistance. Though most of these side effects do reduce once you have been taking the medication for a while, some side effects may persist or be intolerable. You should discuss this with your health care professional.

If you take a GLP-1 agonist while breastfeeding, you should monitor your child for signs of hypoglycaemia, including: being sleepy, or drowsy, irritability, jitteriness, tremors, pallor (paler than usual), sweating, not settling, changes in feeding including poor feeding.

  • Dulaglutide- (as Trulicity®)-
  • No information is available on the clinical use of dulaglutide during breastfeeding.
  • Dulaglutide is a large protein molecule which means it cannot pass into your breastmilk easily. The amount of drug passed into milk is likely to be very low.
  • If dulaglutide enters your milk, it is likely to be destroyed in your child’s stomach, so they are unlikely to absorb it through breastmilk.
  • Dulaglutide may cause you hypoglycaemia when taken with other antidiabetic medications including metformin. This could make bedsharing with your baby unsafe.
  • Monitor your child for signs of hypoglycaemia.
  • Dulaglutide should be used with caution during breastfeeding, especially while nursing a newborn or premature infant.
  • Exenatide- (as Bydureon®)-
  • No information is available on the clinical use of exenatide during breastfeeding.
  • Exenatide is a large protein molecule which means it cannot pass into your breastmilk easily. The amount of drug passed into milk is likely to be very low.
  • If exenatide enters your milk, it is likely to be destroyed in your child’s stomach, so they are unlikely to absorb it through breastmilk.
  • Exenatide stays in the body for a shorter time than other GLP-1 agonists.
  • Exenatide may cause you hypoglycaemia when taken with sulfonylurea drugs. Rarely, exenatide may cause hypoglycaemia when taken alone. This could make bedsharing with your baby unsafe.
  • Monitor your child for hypoglycaemia, and vomiting, diarrhoea or constipation.
  • Caution should be taken during breastfeeding, especially while nursing a newborn or premature infant.
  • Liraglutide- (as Diavic® or Victoza® for Type 2 diabetes and Saxenda® for weight loss)-
  • No information is available on the excretion of liraglutide into milk or clinical use during breastfeeding.
  • Liraglutide is a large protein molecule which means it cannot pass into your breastmilk easily. The amount of drug passed into milk is likely to be very low.
  • If liraglutide enters your milk, it is likely to be destroyed in your child’s stomach, so they are unlikely to absorb it through breastmilk.
  • Liraglutide may cause you hypoglycaemia. This could make bedsharing with your baby unsafe.
  • Monitor your child for hypoglycaemia, and vomiting, diarrhoea or constipation.
  • Caution should be taken during breastfeeding, especially while nursing a newborn or premature infant.
  • Semaglutide- (as Ozempic® for type 2 diabetes and as Wegovy® for weight loss)- Avoid oral tablets while breastfeeding.
  • Some brands of oral semaglutide, such as Rybelsus®, contain the absorption enhancer salcaprozate sodium, which may enter milk and accumulate in infants.
  • Oral semaglutide should NOT be taken while breastfeeding.
  • There is limited information on the clinical use of semaglutide injections during breastfeeding.
  • Semaglutide is a large protein molecule which means it cannot pass into your breastmilk easily. The amount of drug passed into milk is likely to be very low.
  • If semaglutide enters your milk, it is likely to be destroyed in your child’s stomach, so they are unlikely to absorb it through breastmilk.
  • In one study, semaglutide was not detectable in the milk of mothers taking the drug subcutaneously (injected under the skin). Their breastfed infants experienced no adverse effects.
  • Only injectable forms of semaglutide should be used during breastfeeding.
  • Semaglutide may cause you hypoglycaemia. This could make bedsharing with your baby unsafe.
  • Monitor your child for hypoglycaemia, decreased appetite, a swollen abdomen and gastrointestinal side effects including severe reflux, constipation or diarrhoea.
  • Caution should be taken during breastfeeding, especially while nursing a newborn or premature infant.

Dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 Agonist Therapy

Tirzepatide is a new drug which works on two targets. It is a synthetic peptide (short protein) which stimulates insulin secretion and reduces glucagon levels. Some other effects include slowing stomach emptying and reducing appetite. 

It causes better glucose control and weight loss in type 2 diabetics. It is used in people who have not responded well to other therapies first.

Tirzepatide reduces the effectiveness of oral contraceptives and other oral medication due to its impact on digestion. It is not compatible with pregnancy. The manufacturer advises that you should switch to non-oral contraception or add in barrier methods of contraception (e.g. condoms) for four weeks after starting therapy, and for four weeks after each dose increase.

The manufacturer also advises discontinuation at least one month before you become pregnant, which you should consider when planning contraception, and building your family in the future.

  • Tirzepatide- (as Mounjaro®)-
  • There is currently no data available on the safety of tirzepatide during breastfeeding.
  • Tirzepatide is a large protein molecule which means it cannot pass into your breastmilk easily. The amount of drug passed into milk is likely to be very low.
  • If tirzepatide enters your milk, it is likely to be destroyed in your child’s stomach, so they are unlikely to absorb it through breastmilk.
  • Monitor your child for decreased appetite, abdominal distension, GERD (gastroesophageal reflux disease), constipation and diarrhoea.
  • Tirzepatide should be used with caution during breastfeeding, especially while nursing a newborn or premature infant.

SGLT2 Inhibitor Therapy – known as ‘flozins (sodium-glucose cotransporter 2 inhibitor)

SGLT2 inhibitors are not usually prescribed during breastfeeding.

SGLT2 inhibitors reduce the amount of glucose absorbed by your kidneys so you pass excess glucose in your urine. SGLT2 inhibitors are usually added into treatment for people with type 2 diabetes who also have cardiovascular disease or are at risk of cardiovascular disease. They can also be added into treatment regimens where previous treatment options have not worked. Their risk for causing you hypoglycaemia is low.

National guidelines from NICE also recommend the use of dapagliflozin and empagliflozin as options for treating symptomatic chronic heart failure on the advice of a heart specialist.  The way SGLT2 inhibitors help with heart failure is not fully understood, but they help you pass extra fluid when removing excess glucose in your urine and reduce pressure on your kidneys. They are thought to improve energy production in your heart, and reduce inflammation in the cardiovascular system too.

There is no information available on the use of SGLT2 inhibitors while breastfeeding. Manufacturers advise against their use while breastfeeding due to concerns about the theoretical risk to a child’s developing kidneys.

SGLT2 inhibitors are not compatible with pregnancy. If you are taking these medicines, you should discuss if contraception is needed with your healthcare professional and talk to them before planning your next pregnancy so your treatment can be reviewed.

The possibility of side effects in your breastfed child cannot be excluded. There are more suitable treatment options available to treat type 2 diabetes while breastfeeding, which should be considered first. If you have been recommended to take this medication because there are no alternatives for you, please get in touch with the Drugs in Breastmilk Team through our Facebook page or on druginformation@breastfeedingnetwork.org.uk to discuss information available that you can use to discuss risks and benefits of your treatment choices with your healthcare professional to make an informed decision for the health of you and your child.

Thiazolidinediones (glitazones)

Pioglitazone is the only thiazolidinedione available on the market. Pioglitazone works by reducing insulin resistance and improves sensitivity to insulin so your natural insulin produced by your body can work more effectively. Pioglitazone protects pancreatic cells so they produce insulin for longer.

The risk of pioglitazone causing you hypoglycaemia is low.

Pioglitazone encourages weight gain.

Additional caution should be taken if you are feeding a baby whose sole or main source of nutrition is breastmilk (under 6 months or under 12 months of age respectively.)

  • Pioglitazone– (as own brand)-
  • No information is available on the clinical use of pioglitazone during breastfeeding.
  • Pioglitazone is unlikely to pass into breastmilk in clinically significant amounts due to its drug properties. However, pioglitazone stays in the body for a long time and takes up to 5 days to clear after your last dose. Medicines that last in your body for a long time could build up in your breastfed child.
  • Pioglitazone is not usually prescribed during breastfeeding.
  • An alternate drug may be preferred, especially while nursing a newborn or premature infant.
  • Treatment with pioglitazone while breastfeeding should only happen under close monitoring from your diabetes healthcare professional when an alternative is not suitable.
  • Monitor your child for signs of hypoglycaemia– including being sleepy, or drowsy, irritability, jitteriness, tremors, pallor (paler than usual), sweating, not settling, changes in feeding, including poor feeding.
  • You can read more about pioglitazone on the NHS website Pregnancy, breastfeeding and fertility while taking pioglitazone

Sulfonylurea drugs

Sulfonylureas work by stimulating the pancreas to make more insulin. Their risk for causing you hypoglycaemia is moderate. Hypoglycaemia may also be prolonged in duration (last a long time). Sulfonylureas encourage weight gain. There is very little data available on the use of sulfonylurea drugs while breastfeeding. Alternatives are preferred, especially while nursing a newborn or premature infant. Please contact the Drugs in Breastmilk team on druginformation@breastfeedingnetwork.org.uk or through our Facebook page if you need information on taking sulfonylureas whilst breastfeeding. 

Raised cholesterol and breastfeeding – The Breastfeeding Network

Patient information leaflets – what do they mean?

Bibliography