Blood sugar low during pregnancy: what to know

Hypoglycaemia means the glucose available in your blood is too low for your body's immediate needs. It can happen after taking diabetes medicine, missing or delaying a meal, vomiting, exercising more than planned, or eating less because nausea has reduced your appetite. Pregnancy changes your nutritional and medication needs, so a pattern that was manageable before pregnancy may need review now.

Early signs may include shakiness, sweating, hunger, dizziness, headache, blurred vision, tiredness, difficulty concentrating or an unusual change in mood. Nausea can have several causes in pregnancy; it does not by itself confirm hypoglycaemia. People with type 1 diabetes or type 2 diabetes should follow their personalised glucose plan.

Stop what you are doing and sit somewhere safe. Check your glucose if you have been given a meter or sensor and can do so without delaying treatment. Use the quick-acting carbohydrate recommended by your diabetes or maternity team, then recheck or reassess as instructed. Once recovered, eat the planned meal or snack if it is due, and record what happened, including food, medicine, activity and symptoms.

Do not change insulin or other medicines on your own. Contact the clinician managing your pregnancy if episodes repeat, occur overnight, follow vomiting, or happen after a medicine change. A diabetes education programme can help you plan food, activity and sick-day actions.

Call emergency services if you are confused, having a seizure, faint, cannot swallow safely, or do not recover after the agreed treatment. Someone with you should not give food or drink to a person who is unconscious or unable to swallow. Seek same-day maternity or medical advice if episodes keep returning, you cannot keep food or fluids down, or you are worried about reduced fetal movement.

Ask which symptoms should prompt a glucose check, what treatment to carry, how pregnancy changes your medication plan, and what to do during vomiting or a missed meal. Ask whether your monitoring schedule needs adjustment and when to contact the maternity unit.