GDM usually does not give rise to any symptoms, but is detected by a blood test called an oral glucose tolerance test (OGTT) done in the second trimester.

When GDM goes undetected or untreated, the developing foetus may be larger than normal, or there might be more ‘water’ (amniotic fluid) in the womb than normal.

When blood glucose levels are very high, symptoms such as increased thirst, increased urination or weight loss may occur.