QUESTION: How does gestational diabetes lead to diabetes?
Gestational diabetes does not usually “turn into” type 2 diabetes directly. Pregnancy creates extra insulin resistance, and some women cannot produce enough additional insulin to compensate. Gestational diabetes can therefore reveal an underlying tendency toward insulin resistance and reduced pancreatic beta-cell function.
After delivery, glucose often returns to normal, but that underlying tendency may remain. This is why women who have had gestational diabetes have a much higher risk of developing type 2 diabetes later in life.
Answer by Dr. Albana Greca, MD, MMedSc
Hi there,
I want to clarify one important point first. I would not say that gestational diabetes itself damages your body and then becomes type 2 diabetes.
What usually happens is more subtle.
Pregnancy acts almost like a metabolic stress test. During pregnancy, hormones produced largely by the placenta make your cells less sensitive to insulin. This is called insulin resistance.
Insulin allows glucose to move from your bloodstream into your cells. As pregnancy progresses, your body naturally becomes more resistant to insulin.
Most women compensate by producing more insulin. But if your pancreatic beta cells cannot increase insulin production enough, your blood glucose begins to rise and gestational diabetes develops.
The gestational diabetes testing, symptoms and glucose-control guide explains how this condition is detected and managed during pregnancy.
Once the placenta is delivered, the hormonal effects that created much of the pregnancy-related insulin resistance disappear rapidly.
For many women, this means glucose levels return to the normal range and diabetes medication used during pregnancy is no longer required.
But a normal glucose level after delivery does not necessarily mean that the long-term risk has disappeared.
Current evidence does not support the old explanation that pregnancy hormones permanently damage your cells and thereby create type 2 diabetes.
Instead, gestational diabetes often tells us that your pancreatic beta cells have a limited ability to compensate when insulin resistance becomes strong.
Think of it this way: during ordinary life your pancreas may be able to keep glucose normal. Pregnancy asks it to work much harder. Gestational diabetes can reveal a weakness that was not obvious before pregnancy.
No. It means your risk is higher, not that type 2 diabetes is inevitable.
Women with previous gestational diabetes have about a 10-fold higher risk of developing type 2 diabetes compared with women who did not have gestational diabetes. Current estimates suggest a lifetime maternal diabetes risk of roughly 50–60% after gestational diabetes.
Your individual risk is influenced by many things, including:
If you are planning another pregnancy, the gestational diabetes recurrence and prevention guide explains why early testing and preparation are important.
Sometimes, yes.
Pregnancy screening may discover glucose abnormalities that were already present before conception. In some women, what initially appears to be gestational diabetes may actually uncover previously undiagnosed prediabetes or type 2 diabetes.
This is one reason postpartum testing is so important.
If you had gestational diabetes, current recommendations call for a 75-g oral glucose tolerance test about 4–12 weeks after delivery.
This test helps determine whether your glucose has returned to normal or whether prediabetes or diabetes is still present.
The oral glucose tolerance test and interpretation guide explains how this test works.
If your postpartum glucose remains high, it should be properly evaluated rather than assuming that the gestational diabetes simply needs more time to disappear. Persistent high blood sugar after giving birth may indicate persistent glucose intolerance or diabetes.
This is something I particularly want my patients to remember.
Even if your postpartum glucose tolerance test is completely normal, you should continue to be screened for prediabetes and type 2 diabetes throughout your life.
Current recommendations advise repeat screening approximately every 1–3 years.
Yes. A history of gestational diabetes is a warning sign, but it also gives you an opportunity to act early.
Maintaining a healthy weight, staying physically active, choosing a balanced diet and having your glucose checked regularly can reduce your risk or allow prediabetes to be identified before it progresses.
If testing shows prediabetes, your doctor can discuss whether intensive lifestyle changes or medication such as metformin may be appropriate for you.
I would look at gestational diabetes as an important message from your body rather than as a temporary problem that should simply be forgotten after your baby is born.
Pregnancy may have shown us that your body has difficulty producing enough insulin when insulin resistance becomes strong.
Have your postpartum glucose test, continue long-term screening, stay active and work toward a healthy weight. These steps give us the best opportunity to identify problems early and reduce your future risk of type 2 diabetes.
All the best,
Dr. Albana Greca