Skip to main content Site Map

Blood sugar levels and fertility

Why should I control my blood sugar?

Being healthy before pregnancy increases your chances of having a healthy pregnancy.

Elevated sugars are associated with pregnancy complications. Most complications do not occur commonly, but the risk of complications start to increase as blood sugars rise above the healthy range. The risk of complications is highest in women who have diabetes with poor control. Complications may include:

  • Birth defects in the baby
  • Miscarriage
  • High blood pressure complications in later pregnancy
  • Baby growth problems - sometimes too big, but sometimes too small
  • Early delivery
  • Pregnancy loss

Testing for elevated blood sugar levels

Many women do not know if they have normal sugar levels or not. An easy way to find out is to do a simple blood test, called HbA1c. This can be done any time of the day. Your family doctor may have done this and your fertility clinic is likely to test this routinely, as it is important to aim for healthy sugar levels always, but especially before and during pregnancy.

Why is an elevated HbA1c important when planning fertility treatment?

The HbA1c measure provides important information about your health and your long-term health risks.  

What does the HbA1c result mean?

The HbA1c tells us what your sugar levels have been like in your body over the previous six to eight weeks. The result shows us whether your sugar levels are generally in a healthy range or if they are elevated.

If your HbA1c level is close to 30mmol/mol, that is a very normal result, and your sugar levels are very likely to always be in a normal range in your blood stream. If the level is close to 40mmol/mol, we still say that is normal, but it does suggest that, at times, your sugar levels may be above the usual range. However, apart from maintaining a healthy lifestyle, no further treatment is required. Once the level is over 40mmol/mol, it suggests your sugar levels are above the usual range, overall. We call this pre-diabetes. If the level is 50mmol/mol or higher, we call this diabetes. The levels may fluctuate a little over time, so, if you are borderline, the diagnosis may not become clear until further results are looked at. In addition, with careful management, you may be able to reverse prediabetes or early diabetes and return to more normal sugar levels.

The important message is that the HbA1c result, if elevated, should not be ignored. If you ignore it, the level usually worsens over time.

What HbA1c level should I aim to be prior to pregnancy?

This should be discussed with your doctor, as the target is different for different women. If you have type 1 or type 2 diabetes, we recommend you see a specialist who has expertise in helping women with diabetes plan pregnancy.

More information

For more on having a healthy pregnancy if you have diabetes, refer to our diabetes page.