Causes of bleeding in the first trimester of pregnancy

Light spotting may occur as the pregnancy settles into the womb lining or because pregnancy makes the cervix softer and more prone to bleeding. Sex, a pelvic examination, a cervical polyp or inflammation can then trigger spotting. Blood may look pink, red or brown; colour alone cannot identify the cause.

Early pregnancy loss can present with bleeding, cramps, clots or tissue. Ectopic pregnancy can present with vaginal bleeding alongside pain low in the abdomen, sometimes more on one side, or pain at the tip of the shoulder. An ectopic pregnancy develops outside the womb and can cause internal bleeding. Infection of the cervix or vagina is another possible cause, particularly when there is unusual discharge, irritation, pain when passing urine or fever.

Contact your obstetrician, maternity unit or early-pregnancy service and describe when the bleeding began, its amount, whether it is increasing, and any pain, dizziness, clots or tissue. Use a sanitary pad rather than a tampon so you can monitor the flow. If you know your blood group, share it with the clinician because this may affect treatment after bleeding.

Assessment may include questions about your last menstrual period and previous pregnancies, an examination, an ultrasound and blood tests. A single visit may not always establish what is happening, so the clinical team may arrange repeat testing. Do not blame normal daily activity: bleeding or pregnancy loss is not evidence that you caused the problem.

Go to the nearest emergency department or call local emergency services if bleeding is heavy or rapidly increasing, or if you feel faint, dizzy, weak or short of breath. Immediate assessment is also needed for severe abdominal or pelvic pain, pain focused on one side, shoulder-tip pain, collapse, confusion, fever, or feeling acutely unwell. These symptoms can indicate significant blood loss, infection or internal bleeding and should not wait for a routine appointment.

Ask what the examination or scan shows about the location and development of the pregnancy, whether blood tests need repeating, and exactly which change in bleeding or pain should take you to emergency care. You can also ask whether your blood group requires medication and whom to contact if symptoms change outside clinic hours.