In the UK, diabetes is the most common pre-existing medical disorder complicating pregnancy.
This is termed "Gestational diabetes" (GDM) and includes diabetes and also impaired glucose tolerance during pregnancy.
The number of affected women is increasing around the world, and in the UK, diabetes affects 1 in 400 pregnancies.
Most cases are in women who are have already been diagnosed with diabetes. However, gestational diabetes can also occur for the first time during pregnancy, and then it usually disappears after the delivery of the baby.
The risk of recurrence in developing gestational diabetes during a second pregnancy is 66% .
Risk factors for developing GDM
Gestational diabetes appears in the absence of risk factors in more than 50% of cases. However, some of the most common risk factors are listed below:
- Increasing age
- Family history of diabetes
- If you are originally from Asia, North Africa or the Caribbean .
- Previous history of GDM
- Excess weight: if your BMI is over 30, you have 3 times the risk of developing GDM
- If you smoke, you double your risk of GDM
- A short interval or change in between your pregnancies
- Previous history of unexplained miscarriage or stillbirth
- Previous history of your baby weighing above 4.5kg or macrosomia in pregnancy (this is when your baby has a larger head compared to its body)
Screening for GDM
The World Health Organisation (WHO) recommend that GDM is diagnosed using an oral glucose tolerance test (OGTT).
If you have had GDM previously, you should have an OGTT at 16-18 weeks, and a further OGTT at 28 weeks if the results are normal.
If you have any of the other risk factors for GDM, you should be offered an OGTT at 24-28 weeks.
Possible complications of GDM
Pregnancies of women with diabetes are regarded as high-risk for both the woman and the baby.
There are also complications of the diabetes itself, including kidney and eye problems, and high blood pressure.
Increased risks to the baby
- Excessive weight gain and macrosomia
- Genetic abnormalities or deformities in the development of the baby's heart
- Hypoglycaemia (low blood sugar)
- Respiratory distress syndrome and jaundice
- Distress during labour
- Birth injury, usually due to the size of the baby
- Increased risk of caesarean section
- Death during pregnancy, stillbirth or perinatal mortality (i.e. death within the first month of life).
Risks to the mother
- Pregnancy-induced hypertension
- Deep vein thrombosis
- Polyhydramnios (increased fluid)
- Premature labour
- Spontaneous abortion
- Increased risk of caesarean section due to obstructed or different labour
The management of GDM
Women with GDM need to be closely monitored by a specialist team every 1-2 weeks. You will receive routine antenatal care as per NICE guidelines, but also some additional monitoring. The team includes:
- Diabetes specialist
- General practitioner
The main aims are to have good control of your diabetes and regular ultrasound examination of your baby. Your specialist will advise you on your individualised management plan and treatment.