What is gestational diabetes?
Gestational diabetes is a type of diabetes that only happens during pregnancy. If it is well managed, women can still have a healthy pregnancy and a healthy baby.
Gestational diabetes is relatively common, affecting around 4% of pregnancies.
After the baby is born, women with the condition may not have diabetes anymore.
However, gestational diabetes does make women more likely to develop type 2 diabetes in future.
What causes gestational diabetes?
During pregnancy, the placenta, which supplies nutrients to the growing baby, makes hormones that can lead to a build-up of sugar in the blood.
Usually, the pancreas can make enough insulin to cope with that. If it can’t, or the insulin produced is unable to work normally, blood glucose (blood sugar) levels will rise and can cause gestational diabetes.
Who is at risk of gestational diabetes?
Women are more likely to develop gestational diabetes if they:
- Are obese with a BMI of 30 or more
- Are from some ethnic minority groups, including South Asian, black Caribbean or Middle Eastern
- Have previously given birth to a baby weighing 10lbs/4.5kg or more
- Have a family history of diabetes
- Had gestational diabetes in previous pregnancies.
What are the symptoms of gestational diabetes?
Gestational diabetes may not cause any symptoms, but high blood glucose levels, called hyperglycaemia, may cause:
How is gestational diabetes diagnosed?
Because gestational diabetes may not cause any symptoms, it is likely to be identified during routine antenatal appointments.
A blood test may be performed between weeks 8 and 12 of pregnancy.
Women at a higher risk of developing the condition will be offered an oral glucose tolerance test (OGTT) in weeks 24-28, or earlier in their pregnancy if they’ve had gestational diabetes in a previous pregnancy.
The OGTT involves a blood test taken before breakfast, then a carefully measured sugary drink is given. Two hours later another blood test is taken.
Additional testing may be recommended depending on the results and individual circumstances.
How is gestational diabetes treated?
Treatment for gestational diabetes usually involves following recommendations on eating a healthy diet to avoid blood sugar swings and taking exercise.
In some cases medication may also be recommended, including metformin tablets to stimulate the pancreas, or insulin injections to make up for the body not making enough insulin of its own.
What checks will the baby need because of the mum's gestational diabetes?
The baby will be checked during routine antenatal appointments and ultrasound scans. Additional checks and scans may be recommended.
Gestational diabetes will be factored into the birth plan, and in some cases a c-section may be recommended.
The baby will be checked for blood glucose levels soon after being born, and may need special care depending on the results.
Complications of gestational diabetes include a heavier birth weight baby, premature birth, miscarriage and stillbirth. Diagnosing and managing gestational diabetes appropriately reduces the risk of these complications.
What happens to the mum after giving birth?
Because the diabetes was due to the pregnancy, not being pregnant usually means the diabetes goes away.
Any medication for gestational diabetes is usually stopped after giving birth, but monitoring and tests will be arranged to check blood glucose levels are back to normal 6-12 weeks after the baby was born.
Advice will be given on spotting signs of high or low blood sugar.