The blood tests often forgotten after a pregnancy with gestational diabetes

6 days ago

4 min read

If you had gestational diabetes (GDM) during pregnancy, you might have been told that it would resolve after birth. In lots of cases, that's true. However if you have GDM in pregnancy, you have up to a 10x fold risk of developing Type 2 Diabetes in later life, which is why it’s really important to have follow up

One of the most important pieces of postnatal follow-up after you having GDM in pregnancy are some follow up blood tests.

This test can either be a fasting glucose test between 6-13 weeks postnatal, and if the follow up is done after 13 weeks, it can either be a fasting glucose test or a HbA1c test.

It’s also recommended to have HbA1c test annually.

HbA1c measures the proportion of red blood cells with sugar attached to their haemoglobin. Because red blood cells live around 8-12 weeks, this gives an average picture of blood sugar over that stretch, instead of a snapshot like a normal glucose test.

Pregnancy and anaemia can affect HbA1c for lots of reasons which is why it’s only recommended as part of the follow up after 13 weeks

Myth: gestational diabetes goes away once you're not pregnant anymore

It's an easy assumption to make, and largely true in the short term. Once you've given birth, blood sugar levels usually normalise fairly quickly.

Fact: gestational diabetes raises your lifetime risk of type 2 diabetes substantially

Having had GDM doesn't just mean you had to manage diabetes during pregnancy. It's a signal about how your body handles glucose more broadly. Up to half of women who've had gestational diabetes go on to develop type 2 diabetes within ten years. That's a considerable, long-term risk, not a closed chapter.

The test that gets missed

The recommended follow-up is a fasting glucose test at six to twelve weeks postpartum. This checks whether your blood sugar has returned to a normal range, or whether it's showing early signs of moving toward type 2 diabetes.

This test is easy to miss, for a few understandable reasons. The six-to-twelve-week window overlaps with one of the most overwhelming periods of early motherhood: sleep deprivation, feeding, your own physical recovery, and a newborn's needs all competing for attention. Postnatal care in general becomes less structured after the initial weeks, with fewer routine appointments than during pregnancy. And because you likely feel fine, with no symptoms, it's easy to assume the test isn't urgent, even though feeling fine is exactly what makes this test valuable rather than optional.

What this actually means for you

If you had gestational diabetes, this test isn't a formality; it's a genuinely useful early check on a real, elevated risk. Catching a shift toward type 2 diabetes early gives you far more room to act, through lifestyle changes, monitoring, or medical support, than discovering it years later after symptoms have developed.

If you're within that six-to-twelve-week window and haven't been offered this test, it's worth proactively asking your GP for it, rather than waiting for it to be raised. If it's been longer than twelve weeks and you never had it, it's still worth asking; a delayed test is far better than none at all.

One important note: whatever the result, this test is something to discuss with your GP, not something to interpret alone. A single glucose reading needs context; your GP can explain what your specific result means and what, if anything, happens next.

Knowing that you’ve had gestational diabetes is important when thinking about future pregnancies. Having GDM once means you have a higher chance of developing it again, so it’s worth discussing this with your GP if you’re planning another pregnancy. You should be offered diabetes testing when planning a future pregnancy, to check your blood sugar levels before you conceive.

What you can do to reduce your risk, if you had GDM

The good news is that type 2 diabetes risk after GDM isn't fixed; there's a lot within your control. A few things that make a genuine difference:

Stay active where you can. Regular movement, even walking, improves how your body uses insulin.
Prioritise a balanced diet. Focusing on whole foods, fibre, and limiting refined sugar supports healthy blood sugar levels over time.
Keep a gentle eye on weight. Returning to a healthy weight range at a sustainable pace, without pressure or rushing, is linked to lower risk.
Breastfeed, if you're able to and choose to. Breastfeeding has been associated with a modestly lower risk of developing type 2 diabetes after GDM, alongside its many other benefits.
Get retested periodically, not just once. Even with a normal postpartum result, guidelines generally recommend ongoing screening every one to three years, since risk continues over time, not just in the first year.

What to do if the test does show something

If your postpartum test shows raised blood sugar or a diagnosis of prediabetes or type 2 diabetes, it's understandable if that feels like a lot to take in on top of new motherhood. A few things worth knowing:

This can be manageable, especially caught early. Prediabetes and early type 2 diabetes often respond well to lifestyle changes alone, and sometimes medication, particularly when identified promptly rather than years later.
Your GP will guide next steps. This might include referral to a specialist diabetes service, dietary support, or a monitoring plan tailored to you.
You're not starting from nothing. Having already navigated GDM during pregnancy, you likely have real experience with blood sugar monitoring and dietary adjustments, experience that puts you ahead, not behind.
This doesn't have to be managed alone. Ask your GP about local diabetes support services, and don't hesitate to ask questions until the next steps feel clear.

The bottom line

Gestational diabetes typically resolves after birth, but it leaves behind a real, substantial increase in lifetime type 2 diabetes risk. The follow-up glucose test at six to thirteen weeks postpartum is designed to see if your blood sugar control has normalised after pregnancy.Only around six in ten women who should get this test actually do. If that's you, it's worth booking it, and worth asking, even if no one's mentioned it yet.

Written by Hesta Health and validated by a registered postnatal GP.

A final note

If you'd rather have a comprehensive picture of your postnatal health in one go, rather than chasing down individual tests one at a time, the Hesta Health Check covers glucose testing alongside a full review of your recovery, so you're not left wondering what else might be worth asking about.

Learn more about the Hesta Health Check here.