Why can miscarriage happen after a heartbeat is seen?

Seeing cardiac activity shows that the pregnancy was developing at the time of the scan; it cannot predict every later outcome. Early loss may happen when an embryo has a chromosome change that prevents continued development. Other possibilities include an abnormal placenta, bleeding behind the placenta, infection, or a medical condition that needs review. Sometimes testing cannot identify a definite reason.

Normal activity, exercise, intercourse, work, or ordinary emotional upset do not usually explain a miscarriage. Grief and self-blame are common, but they are not evidence of responsibility.

Contact your maternity or gynaecology team to confirm the diagnosis and discuss whether repeat imaging or blood tests are needed. A transvaginal ultrasound can clarify pregnancy location and development when findings are uncertain.

Once loss is confirmed, options may include waiting for the tissue to pass, medicines, or a procedure. Your clinician can explain expected bleeding, pain relief, follow-up, and whether tissue testing is appropriate. Emotional support from a trusted person or counsellor can help while the physical recovery continues.

Seek urgent medical help for heavy bleeding, severe or one-sided abdominal pain, fainting, marked dizziness, shoulder-tip pain, fever, or feeling suddenly very unwell. These symptoms can signal significant blood loss, infection, or an ectopic pregnancy and need prompt assessment.

Ask what the scan shows, whether another scan is needed, which management options fit your situation, how to recognise infection, and when follow-up should happen. You can also ask about future pregnancy planning and support after loss.