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For women with type 1 diabetes

Hypoglycaemia during pregnancy

During the first trimester (the first three months of pregnancy) your blood glucose levels will already be changing. Around the time when most women find out they are pregnant (at four to six weeks), your blood glucose levels may be more unstable, so insulin doses may need to be changed at this time.

From around six to eight weeks, it is common to become more sensitive to insulin, which means the insulin you take works more effectively. This may continue until about 14 weeks (or around three months) into the pregnancy. During this time insulin doses may need to be reduced (usually both daytime and overnight) to avoid frequent and more severe hypoglycaemia (hypos).

Some women also notice that their early warning signs for hypos (such as feeling shaky or sweating) change in pregnancy.

This means that hypos can happen without much—or any—warning, increasing your risk of severe hypos. Frequent blood glucose monitoring can help you with adjusting your insulin doses and reducing this risk. Continuous glucose monitoring can also assist with the early detection of hypos by sounding alarms if your glucose level drops below the target range and by displaying trend arrows to show when glucose levels are falling.

Detecting, preventing and treating hypos are important for your own safety and wellbeing. Your partner, family, friends and colleagues may be able to help you identify hypo symptoms if you are finding it difficult to detect your hypos. Discuss hypo management with your diabetes in pregnancy team.

You also need to remember to check that your blood glucose levels are above 5mmol/L before driving. For more information, refer to the Diabetes and driving booklet.

Severe hypos (when you can’t treat your hypo yourself and you need help from someone else) can be more common during pregnancy, particularly in the first three months. You, your partner and family may like to meet with your doctor or credentialled diabetes educator for an information session on treating severe hypos. They can provide information on available treatments such as glucose gel and glucagon injections (GlucaGen®) and when and how to use these in an emergency. A glucagon injection is an intramuscular or subcutaneous injection that can be used to reverse hypoglycaemia in someone who has a reduced level of consciousness. It helps your body to release glucose stored in your liver and raise your blood glucose levels quickly.

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