Persistent headache in the third trimester: what to know

Late-pregnancy headache may relate to dehydration, poor sleep, migraine, sinus symptoms, vision strain, or raised blood pressure. A serious pregnancy-related condition can also begin with headache, particularly when pain is new, strong, or does not settle. Watch for blurred vision or flashing lights, pain beneath the ribs, sudden swelling, nausea, or feeling unusually unwell.

A headache in pregnancy is not evidence of a brain tumour. Brain tumours and brain metastases can cause headache, but clinicians first consider the full history and examination, including pregnancy-specific causes. Glioblastoma is uncommon and cannot be diagnosed from this symptom.

Contact your maternity unit, obstetric clinician, or pregnancy care team now for advice about a persistent headache. If possible, sit quietly, drink fluids, and record the onset, severity, blood pressure if you have been given a monitor, vision symptoms, and fetal movement. Take medicine only when your maternity clinician has confirmed it is suitable; do not start or combine products based on a past prescription.

Go to urgent maternity or emergency care for severe or rapidly worsening headache, vision loss or flashing lights, weakness, confusion, seizure, fainting, chest or upper-abdominal pain, marked swelling, shortness of breath, fever with neck stiffness, repeated vomiting, or reduced fetal movement. Do not wait for a routine appointment when these occur.

Ask whether your blood pressure and urine need checking, which pain relief is appropriate, whether monitoring of you or the baby is needed, and what symptoms should trigger immediate return. Mention migraine history, recent medicines, and any visual or abdominal symptoms.