Miscarriage
Miscarriage is the most common complication of early pregnancy.
Miscarriage, also known in medical terms as a spontaneous abortion, is the end of a pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can survive independently. It is the most common complication of early pregnancy, with a miscarriage rate of roughly 10% to 20% among women who know they are pregnant, and rates among all fertilizations around 30% to 50%.
- field
- Obstetrics and gynecology
- known_for
- Most common complication of early pregnancy; defined by gestational age and clinical presentation
- risk_factors
- Older parent age, previous miscarriage, tobacco smoke, obesity, diabetes, thyroid problems, drug or alcohol use
- common_cause
- Chromosomal abnormalities in about half of cases
- prevalence
- 10–20% of known pregnancies; 30–50% of all fertilizations
Lore & Background
Terminology has changed over time. Before the 1980s, health professionals used 'spontaneous abortion' for miscarriage and 'induced abortion' for termination. In Britain, the term 'miscarriage' replaced 'spontaneous abortion' to reduce distress and confusion. By the late 1990s, doctors advocated for this change. Terms that cause distress include 'abortion', 'habitual aborter', 'products of conception', 'blighted ovum', 'cervical incompetence', and 'evacuation of retained products of conception'. Most affected women refer to miscarriage as the loss of a baby, and healthcare providers are expected to respect the language the person chooses.
Reader's Guide
Miscarriage is a significant medical and emotional event, representing the most common complication of early pregnancy. Its definition varies by gestational age, with biochemical loss before six weeks, clinical miscarriage before 12 weeks (early) or between 12 and 21 weeks (late), and stillbirth after 20 weeks. The condition affects 10–20% of known pregnancies and up to 50% of all fertilizations. Risk increases with maternal age, from about 10% under age 35 to 45% over age 40. Chromosomal abnormalities cause about half of first-trimester miscarriages. Diagnosis relies on cervical examination, hCG blood tests, and ultrasound. While most miscarriages resolve without intervention, medical or surgical treatment may be needed. The terminology surrounding miscarriage has evolved to reduce distress, with 'miscarriage' preferred over 'spontaneous abortion' in clinical and lay contexts. Emotional support is important, as feelings of sadness, anxiety, or guilt are common. Recurrent miscarriage, defined as two or more losses, may be considered a form of infertility.
Did You Know?
- About 80% of miscarriages occur in the first 12 weeks of pregnancy.
- Chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks.
- The term 'miscarriage' replaced 'spontaneous abortion' in Britain to reduce distress and confusion.
- Women over age 40 have a miscarriage risk of about 45%, compared to about 10% for those under 35.
Frequently Asked Questions
Who is Miscarriage?
Miscarriage is the medical term for a spontaneous abortion, meaning a pregnancy that ends on its own before the embryo or fetus reaches a stage where it could survive outside the womb. It sits within the field of obstetrics and gynecology.
What is Miscarriage's role in the Reproduction And Development series?
As entry 24, Miscarriage represents the single most frequently encountered complication during the earliest weeks of pregnancy. Clinically, it is identified by the gestational age at which it occurs and by the specific symptoms a person presents with.
What is the most common cause behind Miscarriage?
In roughly half of all cases, the underlying trigger is a chromosomal abnormality in the developing embryo. This makes it the single most frequent reason a pregnancy fails to continue past its earliest weeks.
What risk factors increase the likelihood of Miscarriage?
Factors that shift the odds upward include older parental age, a history of prior pregnancy loss, tobacco smoke exposure, obesity, diabetes, thyroid disorders, and the use of drugs or alcohol. None of these guarantee a loss, but each statistically raises the probability.
How prevalent is Miscarriage among pregnancies?
Among pregnancies that are actually confirmed, roughly 10% to 20% end in a miscarriage. When every fertilization event is counted, including those that resolve before a person even realizes they were pregnant, the figure climbs to approximately 30% to 50%.
More in Reproduction And Development 1-24
Elsewhere in the Reproduction And Development universe
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record