Taking medication and insulin for gestational diabetes

Some women can control their glucose levels through diet and exercise alone but the majority will need to take tablets or injections to help control it.

Depending on the levels of glucose in your blood when you are diagnosed, you may be given the option of reducing your levels through dietary changes and exercise alone.

If your levels are still high after a week or two though, you will be offered metformin tablets. If your fasting blood glucose levels are high and you have particular complications such as macrosomia (where the baby is very large) or hydramnios (excessive amniotic fluid), your team may recommend that you start immediate insulin treatment, with or without metformin (as well as dietary and exercise changes).

"If I’d understood more about it, I’d have stuck with the diet and found ways to lower my blood glucose levels. Having insulin is not just a quick fix so that you can eat what you want." Kiera, mum of one

There are two different types of diabetes medication suitable for women with gestational diabetes: tablets and injection.

Tablets - metformin and glibenclamide

In pregnancy, there are two types of tablet that you may be offered to help keep your blood glucose at a healthy level: metformin and glibenclamide.

  • Metformin reduces the amount of glucose made by the liver and helps your body respond better to the insulin you produce naturally
  • Glibenclamide lowers blood glucose by stimulating your pancreas to produce more insulin.

Like all medication, they carry a risk of side effects, so check the patient information leaflet and talk to your doctor about any possible side effects.

Although the patient information leaflet will say that these medications are not to be used during pregnancy, there is strong evidence in the UK for their safety and effectiveness in treating diabetes during pregnancy. Talk to your healthcare team if you have any concerns.

Insulin injections

If tablets are not suitable for you, or are unable to control your blood glucose levels sufficiently, you may need to take the hormone insulin, which only works if it is injected. This means you will need to learn to give yourself insulin injections. If this happens, your diabetes team will show you:

  • how to inject yourself,
  • what times you need to do it,
  • how to keep your insulin
  • where to put the used needles.

They will also explain the risks of low blood glucose (‘hypoglycaemia’) and what to do about it.

Even if you really don’t like needles, try not to worry too much. Insulin injections are not like injections that you may have had in the past. The needle is so fine it is difficult to feel at all, and it does not need to go in deep because the insulin is injected just underneath the skin rather than into a muscle.

"It’s amazing, the needle itself is tiny – you don’t feel it at all. It was straightforward, though you always have to find somewhere to do it – a loo or something." Katie, mum of two

There are various types of insulin, ranging from quick-acting insulin, which needs to be injected at mealtimes, to long-acting insulin, which is injected at the start or end of the day. Some types are more fast-acting, while others take longer to take effect.

If you are having trouble keeping to the right levels with insulin without severe hypoglycaemia, you should be offered pump therapy. You can read more about this on the Diabetes UK website.

If you are taking medication for gestational diabetes, it will usually be stopped immediately after your baby is born.

Diabetes and driving

If you are taking anything for your diabetes, you need to check the regulations with the DVLA because of the risk of having low blood glucose when driving. In general, if you are treating your diabetes through diet or tablets alone and drive a car or motorcycle, you don’t need to tell the DVLA. If you drive larger vehicles or are treated by insulin, you may need to. Either way, as soon as you are diagnosed make sure you tell your car insurer, or your insurance may be invalid. To find out more about diabetes and driving, read the Diabetes UK factsheet. 

Read more


  1. NICE (2015) Diabetes in pregnancy: management of diabetes and its complications from preconception to the postnatal period, National Institute of Health and Care Excellence https://www.nice.org.uk/guidance/ng3
  2. 2.  NHS Choices [accessed April 2015] Gestational diabetes - treatment http://www.nhs.uk/Conditions/gestational-diabetes/Pages/Treatment.aspx
  3. 3. Holt RI,Clarke P et al (2008) The effectiveness of glibenclamide in women with gestational diabetes, Diabetes, obesity, metabolism, 2008 Sep;10(10):906-11. Epub 2007 Dec 17.
  4. 4. Medline Plus [accessed April 2015] Glyburide and Metformin, last revised 09/15/2012www.nlm.nih.gov/medlineplus/druginfo/meds/a699055.html
  5. [4] SIGN (2010) Management of diabetes, a clinical guideline, Scottish Intercollegiate Guidelines Network http://www.sign.ac.uk/pdf/sign116.pdf


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    Last reviewed on March 1st, 2015. Next review date March 1st, 2018.

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    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.

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