Diabetes in pregnancy - treatment options to lower blood glucose (sugar)

For many people, diet and physical activity are enough to keep blood glucose levels in the healthy range for pregnancy, however for some, additional treatment may be required. This leaflet provides you with information about treatment options.

Sometimes blood glucose levels can remain above the recommended range even if you are following the recommended diet and being physically active. This means your body needs additional support, as it cannot produce enough insulin to cope with the extra demands of pregnancy.

It is very important that you do not over-restrict your food to keep your blood glucose levels in the recommended range, although over restriction may result in normal glucose levels, it puts you at risk of nutritional deficiencies. It is better to add in medication to support blood glucose levels, so that you can eat the balanced diet you need to support a healthy pregnancy and prepare for breastfeeding. Understandably women are cautious about taking medication during pregnancy, however, it is better for your baby’s wellbeing to see blood glucose readings within the healthy range for pregnancy supported by medication, than for your baby to be exposed to higher blood glucose levels.

There are very few medications which lower blood glucose levels that are suitable for use in pregnancy; they include Metformin and Insulin, alone or in combination.

Insulin option

When blood glucose levels rise above the recommended range your own insulin production can be ‘topped up’ with an injection of insulin. Needing to give yourself an injection may sound a bit daunting, but the injection is simple. It is given with a short needle into the fatty tissue just under the skin and is much less painful than the finger pricks you are already doing.

We have a demonstration video for you to watch on the Rosie website which will help this to become clear for you.

The insulin that you take does not cross the placenta to your baby.

There are two times for giving insulin, and two types of insulin

If the blood glucose levels are above range on waking, you will be prescribed long-acting insulin also known as background or basal insulin. This is self-administered before bed, about the same time each night. Types of background insulin include – Humulin I and Toujeo.

If the blood glucose levels are above range after eating meals you will be prescribed quick acting insulin, also known as rapid or bolus insulin. This will be self-administered just before eating the meal. This may be at one, two or all of your meals. Types of quick acting insulin include – Trurapi, Novorapid and Humalog.

We will support you to learn how to balance the insulin dose with the food that you eat and your activity levels, to keep your blood glucose levels in the pregnancy range.

The dose of insulin is likely to increase as your pregnancy progresses, this is normal. Daily blood glucose monitoring is very important as it shows when a change in insulin dose is needed.

It is important to keep your blood glucose levels in the healthy range for pregnancy, right up to the point of birth. This means that during labour you will continue to give your usual doses of insulin and remain on the diet until your baby is born.

If blood glucose levels rise above 8.0mmol/l during labour, your care team may advise to change to an infusion of insulin through a drip, for the remainder of the labour.

Once your baby is born you can stop taking the insulin (unless advised otherwise by the pregnancy team) and return to a normal healthy diet but we ask you to continue to monitor your blood glucose levels for 24 hours post birth.

Metformin options

Metformin is a tablet that has been given approval for use in pregnancy by NICE (National Institute for Clinical Excellence) and more recently by the Medicines and Healthcare Products Regulatory Agency and the Commission on Human Medicines. It is known that Metformin crosses the placenta but research has shown no safety concerns around the use of Metformin in pregnancy.

Metformin is an insulin sensitiser; it works by enabling your own insulin to work more effectively. This can mean that the addition of Metformin to your dietary changes and increased activity will be enough to keep your glucose levels in the healthy range for pregnancy.

Metformin can also be useful as an addition to insulin injections. Using them together may keep injected insulin doses lower. This can help prevent excessive pregnancy weight gain and therefore improve pregnancy outcomes.

Metformin is not always the optimal treatment option. There are medical conditions or pregnancy complications that may mean insulin would be a better choice. Your pregnancy team will discuss this with you.

Metformin can sometimes cause transient (short lived) gastric (stomach) upset. This side effect can be minimised by starting on a low dose, and building up the dose slowly every 3-4 days, if required, and by taking the tablet with or immediately after food. The effect of Metformin on your blood glucose level is not as immediate as insulin, and may take a few days to see the full effect.

It is important to keep your blood glucose levels within the healthy range for pregnancy, right up to the point of birth. This means that during labour, you will continue to take your usual doses of Metformin and remain on the diabetes in pregnancy diet until your baby is born. If your blood glucose levels rise above 8.0mmol/l during labour, your care team may advise that you change to an infusion of insulin through a drip, for the remainder of your labour.

Once your baby is born you should stop taking the Metformin (unless you have been advised otherwise by the pregnancy team) and return to a normal healthy diet, but we ask you to continue to monitor your blood glucose levels for 24 hours post birth.

Starter doses for metformin

Option 1: Metformin with evening meal

This can either be prescribed to support your waking/fasting blood sugar or your post evening meal blood sugar

1.If taken to support your waking/fasting blood sugar

• Start with 500mg (one tablet) Metformin after a few mouthfuls of your evening meal or at the end of your meal. Take this dose for the first 3 days.
• If you are tolerating this dose and your fasting blood glucose remain at 5.3mmol/l and above at day 4 please increase to the maximum dose of 1g (two tablets) Metformin that evening.
• Please continue on 1g Metformin, and if after a week of taking this dose your fasting blood glucose remains at 5.3mmol/l or above please contact the diabetes in pregnancy teamagain.

2.If taken to support your post evening meal blood sugar

• Start with 500mg (one tablet) Metformin after a few mouthfuls of your evening meal or at the end of your meal. Take this dose for the first 3 days.
• If you are tolerating this dose and your post-meal blood glucose reading is 7.8mmol/l and above at day 4 please increase to the maximum dose of 1g (two tablets) Metformin that evening.
• Please continue on 1g Metformin, and if after a week of taking this dose your post-meal blood glucose remains at 7.8mmol/l or above please contact the diabetes in pregnancy team.

Option 2: Metformin with breakfast

• Start with 500mg (one tablet) Metformin after a few mouthfuls of your breakfast or at the end of your meal. Take this dose for the first 3 days.
• If you are tolerating this dose and your post-meal blood glucose reading is 7.8mmol/l or above at day 3 please increase to the maximum dose of 1g (two tablets) on day 4.
• Please continue on 1g Metformin, and if after a week of taking this dose your post-meal blood glucose remains at 7.8mmol/l or above please contact the diabetes in pregnancy team.

Option 3: Metformin with lunch

• Start with 500mg (one tablet) Metformin after a few mouthfuls of your lunch or at the end of your meal. Take this dose for the first 3 days.
• If you are tolerating this dose and your post-meal blood glucose reading is 7.8mmol/l or above at day 3 please increase to the maximum dose of 1g (two tablets) on day 4.
• Please continue on 1g Metformin, and if after a week of taking this dose your post-meal blood glucose remains at 7.8mmol/l or above please contact the diabetes in pregnancy team.

If you find that you do not tolerate taking 1g with a meal but did tolerate 500mg please reduce back to this dose and continue to monitor your blood glucose readings.

Your metformin dose may be further increased as necessary. The maximum total daily dose of Metformin we recommend is 2g which is typically taken as 1g twice daily, always taken with food and not on an empty stomach to reduce potential gastric symptoms.