The following information is to be used as a guide to and at the discretion of the end-user and should not replace a doctor’s opinion.
OVERVIEW
Gestational diabetes (GDM) is high blood sugar (glucose) that starts or is first discovered during pregnancy. It’s different from type 1 or type 2 diabetes because it happens only while you are pregnant (although it raises your chance of later developing type 2 diabetes).
During pregnancy your placenta makes hormones that make your cells less sensitive to insulin. Your pancreas must make more insulin to keep your blood sugar normal. If your pancreas can’t keep up, your blood sugar rises — that is GDM.
Gestational diabetes is common and treatable. While there are certain risk factors that make developing GDM more likely, early diagnosis and good management greatly reduce risks to you and your baby. Early testing, healthy eating, physical activity, and working closely with your antenatal team usually lead to safe pregnancies and healthy babies.
GESTATIONAL DIABETES IN SOUTH AFRICA
GDM in South Africa has a high prevalence, estimated to be 11.5% and possibly as high as 18% to 25%. This is linked to a combination of increasing lifestyle-related risk factors, such as obesity, and underlying genetic predispositions.
- South Africa is experiencing a dramatic increase in obesity, with nearly 70% of women being overweight or obese. Urbanisation and socioeconomic changes have led to a rapid shift in diet and lifestyle, contributing to higher rates of obesity and non-communicable diseases like type 2 diabetes, which can increase GDM risk.
- Certain ethnic groups in South Africa, such as people of Indian descent, have a higher predisposition to developing diabetes, including GDM.
RISK FACTORS FOR GESTATIONAL DIABETES
You are more likely to develop GDM if you have one or more of these risk factors:
- Are overweight or obese (high body mass index).
- Are older than 35 at pregnancy.
- Have a close family member with type 2 diabetes (parents or siblings).
- Had GDM in a previous pregnancy.
- Have had a very large baby (over 4 kg) previously or a baby who had breathing or blood sugar problems at birth.
- Have polycystic ovary syndrome (PCOS) or prior high blood sugar.
- Are of a population group with high diabetes rates (South Africa’s overall diabetes burden means risk is higher for many women).
If you have any of these, you may be tested earlier in pregnancy.
SCREENING FOR GESTATIONAL DIABETES
Most women have a screening test between 24 and 28 weeks of pregnancy, as this is when the pregnancy hormones that block insulin are strongest.
However, if you have any of the risk factors, you should test at your first antenatal visit to check whether or not you already have diabetes.
RISKS OF UNTREATED GESTATIONAL DIABETES
If untreated, GDM raises risks for both mother and baby:
- For the baby: larger birth weight (macrosomia), birth injuries, early (neonatal) low blood sugar after birth, increased chance of needing NICU care, and higher risk of obesity and diabetes later in life.
- For the mother: higher chance of high blood pressure and pre-eclampsia during pregnancy, more likely to need a caesarean (C-section), and higher lifetime risk of developing type 2 diabetes.
Good treatment reduces most of these risks.
TREATING GESTATIONAL DIABETES
The main goals of GDM treatment are to keep blood sugar within a healthy target range to protect the baby and reduce pregnancy complications.
DELIVERY AND NEWBORN CARE
If you have GDM your obstetric team will monitor foetal growth and may plan delivery timing based on glucose control and baby size. Babies born to mothers with GDM are checked soon after birth for low blood sugar and other issues. With good control and appropriate care, most women with GDM have healthy deliveries and babies.
After the baby is born:
- Mother: Have a glucose test 6–12 weeks after delivery to check if blood sugar is back to normal. You remain at higher risk of type 2 diabetes—regular checks every 1–3 years are recommended, and healthy lifestyle habits are important.
- Child: Babies exposed to GDM should be monitored as they grow because of higher long-term risks of obesity and metabolic problems. Good infant feeding and healthy lifestyle choices reduce risk.
PREVENTING / LOWERING YOUR RISK OF GESTATIONAL DIABETES IN FUTURE PREGNANCIES
- Achieve a healthy weight before pregnancy, if possible.
- Eat a balanced diet, be physically active, and stop smoking.
- If you had GDM before, aim for close monitoring and possible earlier glucose testing in future pregnancies.
- Small changes before pregnancy and immediately postpartum (weight loss if needed, healthy eating, regular physical activity) lower the risk of future diabetes.
FURTHER READING
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