Gestational diabetes is when a pregnant person who does not already have diabetes begins to have high blood glucose in later pregnancy. It affects around 4-8% of pregnancies.
During pregnancy, you need for insulin increases as your body begins to resist the effects of this hormone to channel more glucose over to your baby for growth. Most people’s bodies increase insulin production enough to allow enough glucose into their cells to fuel their bodies, but some bodies do not increase insulin production enough, and this leaves more glucose in their blood than is healthy. This is gestational diabetes.
High glucose levels in pregnancy can cause your baby to grow bigger than they would have otherwise, and can increase your chances of having a miscarriage, stillbirth, or premature baby. Larger babies have the potential to cause more difficult births, with increased chances of shoulder dystocia and caesarean birth. After they are born, babies of parents with diabetes may have trouble breathing well and may have low blood sugar as their body gets used to not having a constant supply of glucose.
For these reasons, it is important to control your blood glucose well in pregnancy. If you have gestational diabetes, then you will need to check your blood glucose levels at least four times a day – first thing in the morning, and one or two hours after each meal. Your midwife can prescribe a blood glucose monitor for you. You should be aiming for a morning glucose reading of under 5mmol/L, and a one-hour post-meal reading of under 7.4mmol/L or a two-hour post-meal reading of under 6.7mmol/L.
The first line treatment for gestational diabetes is a healthy diet and exercise, and the diabetes in pregnancy team will advise you on what that might look like. If your blood glucose readings are higher than they should be even with diet and exercise, then you may need medication to help manage your diabetes. The diabetes in pregnancy team will support you in this. If you do need medication to help control your diabetes, then you may be offered an induction of labour.
Once baby is born, it is recommended that they have blood glucose readings done after birth and before their first few feeds, so it is recommended that you stay in your birthing facility for these tests. You will usually have to do a few more blood glucose tests, then your diabetes medication is usually stopped.
Gestational diabetes usually goes away after pregnancy, but you should have an HbA1c blood test three months after you give birth to check. If you have gestational diabetes in one pregnancy, you have about a 50% chance of getting it in a subsequent pregnancy. You also have about a 50% chance of getting type 2 diabetes within 5 years, so it is important to have an HbA1c blood test every year after your three month blood test.