Blood glucose monitoring during pregnancy, for women with type 1 diabetes
It is essential to monitor your blood glucose levels frequently during your pregnancy. You will be asked to monitor before meals and one to two hours after meals. You may, at times, be advised to do some extra monitoring, such as before bed and overnight (to look for hypos). You should also check your blood glucose levels before driving.
Monitoring will help you and your doctor to get a better understanding of your blood glucose levels, so you can adjust your insulin to achieve the best possible management of your diabetes. Extra blood glucose monitoring can also help you reduce the tendency to have hypos and big swings in your blood glucose levels.
Continuous glucose monitoring (CGM) or flash glucose monitoring (Flash GM) may be suggested when you are planning and preparing for pregnancy, during your pregnancy or immediately after your baby is born.
CGM devices are small wearable monitors that measure and display your glucose levels throughout the day and night. They can be programmed to sound alarms and send warnings if your glucose levels are outside your set target range. CGM devices also display arrows to show whether your glucose levels are rising, falling or steady and how quickly this is occurring.
CGM uses a sensor placed under the skin to measure the level of glucose in the fluid between your cells. This information is sent via a transmitter to a wireless receiver, insulin pump or smartphone. The receiver allows you to view and store your glucose data, which can be uploaded for you (and your health care team) to review.
A Flash GM device is like a CGM device, except that it does not have a transmitter and you have to scan the sensor with a reader, smartphone or smart device to check your glucose level. In Australia, this technology is available in FreeStyle Libre and FreeStyle Libre 2. FreeStyle Libre does not have alarms, but has trend arrows to indicate if glucose levels are rising, falling or steady and how quickly they are changing. FreeStyle Libre 2 has optional real-time alarms for high or low glucose levels and signal loss. Scan results display the previous eight hours of glucose data. The graphs on the Flash GM reader can be reviewed to look for patterns and trends in glucose levels. A Flash GM device does not connect to an insulin pump.
CGM or Flash GM can help you and your health professionals make decisions about changes to insulin doses or pump settings as well as food choices and physical activity. When planning and preparing for pregnancy, this may help you with keeping your glucose levels in the target range advised by your health professionals. These devices don’t replace self-blood glucose monitoring but can reduce the number of daily finger-prick blood glucose checks you need to do.
The Australian Government provides access to fully subsidised CGM and Flash GM through the CGM Initiative as part of the NDSS to women with type 1 diabetes who are actively planning pregnancy, pregnant or immediately post-pregnancy. To be eligible for access, women with type 1 diabetes need to be assessed by an authorised health professional and meet certain criteria. Ask your diabetes in pregnancy team for more information or read more at Continuous and flash glucose monitoring.
Blood glucose targets
Your diabetes in pregnancy team will discuss individual pregnancy blood glucose targets with you. They will encourage you to check your blood glucose levels frequently and will work with you to keep these as close as possible to the target range.