Miscarriage: causes, signs, types, diagnosis and support

Frequency and risk factors

Among people who know they are pregnant, miscarriages are common. Estimates vary, but a substantial minority of recognized pregnancies end in loss. Risk increases with advancing maternal age and with certain medical conditions. Other factors associated with increased risk include chromosomal anomalies in the pregnancy, some uterine abnormalities, untreated chronic disease, and lifestyle factors such as smoking and excessive alcohol use. Human reproductive biology contributes to a background rate of early losses in humans, especially in the first trimester.

Causes and types

Not all losses have an identifiable cause, but frequent contributors are:

• Chromosomal or genetic abnormalities of the embryo or fetus.
• Anatomical problems of the uterus or cervix.
• Hormonal or immune disorders, and some infections.
• Environmental exposures and lifestyle risks.

Clinicians also describe miscarriages by clinical stage: threatened, inevitable, incomplete, complete, and missed losses. These categories describe symptoms and findings on examination or ultrasound rather than cause.

Diagnosis and management

Diagnosis relies on symptoms (vaginal bleeding, cramping, loss of pregnancy symptoms), pelvic examination, ultrasound imaging, and serial measurements of pregnancy hormones (hCG). Management options depend on the clinical situation and patient preference and may include expectant (watchful) management, medical treatment to expel pregnancy tissue, or surgical procedures such as dilation and curettage. Follow-up ensures that bleeding and infection are addressed and that physical recovery is complete.

Emotional impact and follow-up

Pregnancy loss can be emotionally painful for individuals and partners. Supportive care, counselling, and clear information about future fertility are important. Most people who have a single miscarriage go on to have healthy pregnancies. When losses are recurrent (commonly defined as two or three consecutive losses), clinicians typically offer further evaluation and specialist referral to investigate possible causes.

Prevention and when to seek care

Not all miscarriages are preventable, but preconception health optimisation—managing chronic conditions, avoiding tobacco and excessive alcohol, maintaining a healthy weight, and taking recommended prenatal vitamins—can reduce some risks. Seek urgent care for heavy vaginal bleeding, severe pain, fever, or other concerning symptoms. For more information on pregnancy care and early pregnancy issues see resources at trusted medical sources.