What causes gestational diabetes?

Insulin is produced by the pancreas (an organ near the stomach), which keeps blood glucose levels under control. During pregnancy, the body produces hormones that work against insulin; this means that more insulin is needed to keep the blood glucose normal. If not enough insulin is produced to do this, blood glucose rises and diabetes develops.

When blood glucose is sufficiently high, excess glucose gets filtered out by the kidneys and passes into the urine. If you have diabetes, you may need to use the bathroom more often, or feel very thirsty because of this.