Heavy bleeding in the first trimester

Light spotting can occur for different reasons, but heavy bleeding is more concerning and cannot be assessed safely from flow alone. Possible causes include changes at the cervix, a threatened or ongoing miscarriage, or an ectopic pregnancy, where a pregnancy develops outside the womb. One symptom does not confirm any diagnosis. Pain on one side, shoulder-tip pain, weakness, or dizziness can be especially urgent because internal bleeding may not be visible.

Contact an urgent maternity or medical service and state how far along the pregnancy may be, how the bleeding began, and whether you have pain or clots. Use a pad to observe the flow rather than inserting a tampon. Keep your phone available and, if you feel unwell, ask someone to stay with you. Do not drive yourself if faint, severely weak, or in intense pain. Assessment may include an examination, blood tests, and ultrasound.

Seek emergency help now for heavy or continuing bleeding, severe or one-sided abdominal pain, shoulder-tip pain, faintness, dizziness, marked weakness, or collapse. Prompt assessment is also needed if you have known or possible pregnancy and any bleeding that worries you. Symptoms can change quickly, so do not wait for bleeding to settle when you feel unwell.

Ask what the examination and scan show, whether the pregnancy is in the womb, whether blood tests need repeating, what symptoms require emergency help, and how you will be supported during follow-up.