Pre-eclampsia usually develops after 20 weeks and involves high blood pressure along with signs that organs such as the kidneys or liver are affected. It can be dangerous for both parent and baby if not managed, which is why blood pressure and urine are checked at antenatal visits.
Warning symptoms include a severe or persistent headache, vision problems like blurring or flashing lights, pain just below the ribs, sudden swelling of the face, hands, or feet, vomiting, and feeling generally very unwell. Some people have no symptoms and it is picked up only on checks.
If you notice these warning signs, contact your maternity team urgently or seek emergency care. The only definitive treatment is delivery of the baby, so timing and monitoring are managed carefully by specialists. Attending all antenatal appointments helps catch it early.