miscarriage

Miscarriage is the spontaneous loss of a pregnancy before viability, typically before 20 weeks of gestation. It is the most common type of pregnancy loss; losses after 20 weeks are termed stillbirth.

Most first-trimester miscarriages result from fetal chromosomal abnormalities. Other factors include maternal medical conditions (diabetes, thyroid disease, autoimmune disorders such as antiphospholipid syndrome), uterine or cervical problems, infections, and exposure to harmful substances. In many cases no clear cause is found. Recurrent miscarriage is defined as three or more consecutive losses.

Symptoms often include vaginal bleeding and cramping; passage of tissue may occur. Some cases have no early signs. Diagnosis is based on dating, ultrasound showing nonviability, and decreasing hCG levels; additional tests may assess anatomy, hormonal and immune factors.

Management depends on gestational age and preferences. Options include expectant management, medical treatment with misoprostol, or surgical management such as dilation and curettage. Most people recover physically and can have future pregnancies. The risk of another miscarriage is higher after a prior loss, especially with recurrent miscarriages.

Psychosocial effects are common; support from healthcare providers, family, and counseling can help. Prevention is not always possible, but controlling chronic conditions, avoiding tobacco and excessive alcohol, maintaining a healthy weight, and early prenatal care may reduce risk in some cases.

See also Stillbirth; Recurrent miscarriage.