Threatened miscarriage

Disease Description (Causes and Symptoms)

• Definition: A condition involving bloody vaginal discharge or vaginal bleeding before 20 weeks of pregnancy while the cervix remains closed (threatened abortion, Threatened abortion).
• Causes and pathophysiology: In early pregnancy, bleeding can occur easily because the placenta (chorionic villi) penetrates the endometrium and connects with uterine blood vessels. Causes may include the implantation site (e.g., near the cervix), partial separation of the placenta, abnormalities in the fertilized egg or fetus, and cervical lesions.
• Main symptoms: Spotting or heavy vaginal bleeding, abdominal pain (intermittent or dull), lower back pain, and pelvic pressure. If the bleeding does not stop or the pain is severe, the likelihood of a progressing miscarriage increases.
• Differential diagnosis: Ectopic pregnancy, other forms of miscarriage (inevitable miscarriage, incomplete miscarriage, etc.), cervical polyps or cervicitis, and ovarian disorders (such as torsion).

Treatment Methods and Precautions

• Basic principles: There is currently no definitive treatment that changes the course of threatened abortion itself. Most treatment focuses on symptom relief and observation of the course.
• Conservative management
  • Rest (limiting strenuous activity and, if necessary, recommending abstinence from sexual intercourse). However, there is insufficient strong evidence that strict bed rest changes the prognosis.
  • Pain control: Acetaminophen (Tylenol) is preferred. Nonsteroidal anti-inflammatory drugs (NSAIDs) should be used according to a doctor's instructions (general short-term use may be possible, but caution is needed in early pregnancy).
  • If the bleeding is mild, observation through outpatient follow-up (ultrasound and blood tests).
• Medication treatment (selective)
  • Progesterone supplementation: Supplementation may be considered in some patients with findings of low progesterone or a history of recurrent miscarriage. The indications and expected effects vary depending on the individual patient's circumstances, so consultation with the treating doctor is necessary.
  • Rh-negative mothers: If bleeding occurs, administration of Rh immune globulin may be considered (to prevent antibody formation).
• Emergency and interventional treatment
  • If there is heavy bleeding, anemia, or hypovolemia: Emergency treatment such as detailed blood tests (CBC), fluids, and blood transfusion; removal of retained products in the uterus may be considered if necessary (when miscarriage has been confirmed).
  • Inpatient treatment if vital signs are unstable or bleeding is severe.
• Follow-up tests: Vaginal ultrasound (primarily transvaginal ultrasound), and serial monitoring of serum β-hCG and progesterone levels.
• Risk of complications and precautions: Persistent bleeding increases the likelihood of progressing to spontaneous miscarriage and increases the subsequent risks of preterm birth, low birth weight, and perinatal death. Additional treatment is necessary if cervical or intrauterine infection develops.

Checklist Before an Outpatient Visit (Items to Bring and Things to Confirm)

• Items to bring/prepare
  • A list of medications currently being taken (including prescription drugs, herbal medicines, and supplements)
  • Previous test results (ultrasound images and blood test results) or examination records, if available
  • The first day of the last menstrual period (for calculating gestational age), and previous obstetric history (pregnancies, births, and miscarriages)
  • Medical history (especially bleeding disorders, blood type and Rh status, and drug allergies)
• Symptom records
  • The time bleeding began, frequency, amount (such as the interval between pad changes), blood color (bright red/dark brown), and the nature and intensity of accompanying pain
  • Whether systemic symptoms such as fever or dizziness are present
• Example questions (can be shown directly to the doctor during the visit)
  • How should I measure the amount of bleeding? When should I go to the emergency room?
  • My blood type (Rh) is negative. Do I need immune globulin?

Examples of General Questions to Ask the Doctor

• Given my current condition, what is the likelihood of miscarriage (prognosis)?
• What additional tests should I have, and by when (ultrasound, β-hCG, progesterone, etc.)?
• What is the purpose of the prescribed medication, and what are its possible side effects?
• What activities should I avoid in daily life while I am bleeding (sexual intercourse, exercise, etc.)?
• How will pregnancy care proceed in the future (follow-up intervals, schedule of prenatal tests, etc.)?

Examples of Condition-Specific Questions

• My blood type is Rh-negative. Should I receive Rh immune globulin immediately for this bleeding?
• Is progesterone supplementation likely to help in my case (for example, when a heartbeat is not visible on ultrasound but the embryo is small, or when there is a history of recurrent miscarriage)?