Dizziness During the Third Trimester: What You Should Know

Late pregnancy changes circulation and puts extra demands on the body. You may feel lightheaded after standing, lying flat, missing a meal, or becoming too warm. A spinning sensation is different from feeling faint, so describe it clearly to your maternity team.

The growing uterus can affect blood flow when you lie flat, and standing quickly can briefly lower blood pressure. Dehydration, heat exhaustion, or hypoglycaemia can also cause dizziness. Anaemia, including iron deficiency anaemia, may cause tiredness and breathlessness alongside lightheadedness. Inner-ear problems such as benign paroxysmal positional vertigo can cause spinning when you turn your head. These symptoms do not identify one cause on their own.

Stop what you are doing and sit or lie on your side in a cool place. Take slow sips of fluid and eat a suitable snack if you have missed food and your maternity team has not advised otherwise. Move from lying to sitting, pause, then stand with support. Avoid prolonged standing and overheating. Note the trigger, duration, fetal movement, fluid intake, and any bleeding, pain, headache, or visual change.

Contact your maternity team promptly for repeated or persistent dizziness, fainting, severe headache, visual changes, upper abdominal pain, sudden swelling, breathlessness, chest pain, bleeding, fluid leakage, contractions, or reduced fetal movement. Emergency help is needed for collapse, severe breathing difficulty, new weakness, confusion, or trouble speaking. Do not drive yourself while dizzy.

Ask whether your blood pressure, blood count, iron status, hydration, and medicines should be reviewed. Tell the clinician how far along you are, whether symptoms occur when lying flat or standing, and whether your baby’s movements have changed.