Miscarriage

Miscarriage, also known as spontaneous abortion or early pregnancy loss, refers to the natural death and expulsion of an embryo or foetus before it can survive independently, typically before 20 weeks of gestation. Miscarriages can be "early" (before 12 weeks) or "late" (12-21 weeks).

An ultrasound showing a gestational sac containing a yolk sac but no embryo

The primary signs of a miscarriage include vaginal bleeding, which may or may not be accompanied by pain. Other symptoms can be abdominal pain, cramping, and the passage of tissue or blood clots from the vagina. While bleeding in early pregnancy can be a sign of a threatened miscarriage, many women who experience bleeding do not miscarry.

Risk Factors

Miscarriage can occur for various reasons, many of which are not identifiable. Risk factors include:

• Age: Increased risk with maternal age, especially after 35.
• Lifestyle Factors: Smoking, obesity, drug and alcohol use.
• Medical Conditions: Diabetes, thyroid disorders, autoimmune diseases.
• Infections: Listeriosis, toxoplasmosis, and others.
• Genetic Factors: Chromosomal abnormalities are found in more than half of first-trimester miscarriages.

Diagnosis

Diagnosis of a miscarriage can involve:

• Physical Examination: Checking if the cervix is open or sealed.
• Ultrasound: To confirm the presence of an intrauterine pregnancy.
• Blood Tests: Measuring levels of human chorionic gonadotropin (hCG).

Ultrasound Criteria

Miscarriage is diagnosed if:

• Crown-rump length is at least 7 mm with no heartbeat.
• Mean gestational sac diameter is at least 25 mm with no embryo.
• Absence of an embryo with a heartbeat after a specified period following initial ultrasound findings.

Transvaginal ultrasonography after an episode of heavy bleeding in an intrauterine pregnancy that had been confirmed by previous ultrasonography. There is some widening between the uterine walls, but no sign of any gestational sac, thus, in this case, being diagnostic of a complete miscarriage.

Transvaginal ultrasonography, with some products of conception in the cervix (to the left in the image) and remnants of a gestational sac by the fundus (to the right in the image), indicating an incomplete miscarriage

A 13-week foetus without cardiac activity located in the uterus (delayed or missed miscarriage)

Classification

Miscarriages are classified into several types:

• Threatened Miscarriage: Any bleeding during the first half of pregnancy.
• Anembryonic Pregnancy: Gestational sac develops without an embryo.
• Inevitable Miscarriage: Cervix dilates, but the foetus is not yet expelled.
• Complete Miscarriage: All products of conception are expelled.
• Incomplete Miscarriage: Some products of conception remain in the uterus.
• Missed Miscarriage: Embryo or foetus has died, but miscarriage has not yet occurred.
• Septic Miscarriage: Infected tissue from a missed or incomplete miscarriage.
• Recurrent Miscarriage: Multiple consecutive miscarriages.

Treatment

Management of miscarriage may involve:

• Expectant Management: Waiting for the miscarriage to complete naturally.
• Medication: Misoprostol to help expel tissue.
• Surgical Treatment: Vacuum aspiration or curettage for incomplete or missed miscarriages.
• Emotional Support: Essential to help parents cope with the loss.

Prevention

While not all miscarriages can be prevented, some steps can reduce risk:

• Prenatal Care: Regular check-ups and monitoring.
• Healthy Lifestyle: Avoiding smoking, alcohol, and drugs.
• Medical Management: Controlling chronic diseases such as diabetes and thyroid disorders.

Psychological and Emotional Effects

Miscarriage can lead to significant emotional distress, including anxiety, depression, and grief. Support from healthcare providers, family, and friends is very important.

A cemetery for miscarried foetuses, stillborn babies, and babies who have died soon after birth

Self-assessment MCQs (single best answer)

What is another term for miscarriage?

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Which of the following is NOT a common sign of a miscarriage?

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Which of the following is a risk factor for miscarriage?

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What is the first step in diagnosing a miscarriage?

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Miscarriage can be diagnosed via ultrasound if the crown-rump length is at least:

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Which type of miscarriage involves the cervix dilating but the foetus not yet being expelled?

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Which treatment for miscarriage involves waiting for the miscarriage to complete naturally?

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Which of the following is NOT a method to reduce the risk of miscarriage?

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Which type of miscarriage is characterised by the presence of an infected tissue from a missed or incomplete miscarriage?

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What psychological effects can a miscarriage lead to?

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