Most people are familiar with the two main types of diabetes — Type 1, where patients cannot make insulin and need insulin injections for life; and Type 2, where patients have insulin resistance and cannot use insulin properly. There is another kind of diabetes that occurs only in pregnancy, known as gestational diabetes mellitus.

GDM occurs in pregnancy in someone who was never diagnosed with diabetes before, and it usually resolves after delivery. But women with GDM are at risk for GDM with future pregnancies, and an increased chance of developing Type 2 diabetes later on. In GDM, babies may be too big and there is risk for early delivery and complications during delivery.

GDM is diagnosed with an oral glucose tolerance test, where blood samples are drawn before and after drinking 75 grams of glucose. This is usually done around the sixth month of pregnancy, but Filipino women have been found to have an increased risk for GDM and the OGTT should be done at the first prenatal visit, especially if you are 25 years old or older and have a first-degree relative with Type 2 diabetes. Testing should also be done in women with a history of irregular menstrual periods and polycystic ovary syndrome, who are overweight or obese before pregnancy, or who have previously delivered a baby weighing eight pounds or more.

In GDM, it will also be necessary to check your blood glucose levels by using either a traditional glucometer and pricking your finger to test, or with continuous glucose monitoring. If you have GDM, consult with an endocrinologist who can help you decide on which method is best for you and how often you need to check.