Placenta previa

Placenta previa (Placenta previa)

1) Disease description (causes and symptoms)

• Definition: A condition in which the placenta is located toward the cervix (internal cervical os) rather than in its normal position in the uterine fundus, completely, partially, or marginally covering the cervix, or lying very close to it.
• Pathophysiology and causes/risk factors:
  • Risk is increased by previous cesarean section or uterine surgery (such as endometrial resection), multiparity (a high number of pregnancies), advanced maternal age, multiple pregnancy, and previous intrauterine miscarriage procedures.
  • Because the placenta is located in the lower part of the uterus, painless bleeding occurs when the cervical canal opens or when blood vessels at the placental attachment site are damaged due to changes in the fetus or uterus.
  • It may be accompanied by placenta accreta spectrum, in which case the risk of bleeding increases.
• Main symptoms:
  • Painless antepartum vaginal bleeding (usually occurring after the middle of pregnancy, especially in the latter half of the second trimester to the third trimester).
  • Bleeding may range from slight to severe and may recur.
  • Signs of worsening fetal status (decreased fetal movement, abnormal fetal movement, etc.) or preterm delivery may appear.

2) Treatment methods

• Diagnosis and initial management:
  • Confirmation: Confirm the placental location with ultrasound (transabdominal and, if necessary, transvaginal ultrasound). Vaginal (digital) examination is prohibited when the cause of bleeding is not clear.
  • If stable, hospital admission and observation, with monitoring of the amount and frequency of bleeding, fetal movement, fetal heart rate, and maternal vital signs.
• Conservative (expectant) treatment:
  • In cases of mild or stopped bleeding, bed rest, pelvic rest (no sexual intercourse, vaginal douching, or intravaginal examination), and regular follow-up ultrasound.
  • If necessary, corticosteroids (e.g., betamethasone) may be used to promote fetal lung maturation when there is a risk of preterm birth.
  • Prepare blood in consideration of the possibility of transfusion.
• Delivery and surgical treatment:
  • In general, when the placenta covers the cervix, cesarean section is recommended for delivery (planned cesarean section, usually targeting 36–37 weeks, but individualized).
  • Emergency cesarean section is performed in cases of severe bleeding or when the lives of the mother or fetus are threatened.
  • If excessive bleeding occurs during surgery, uterotonics, uterine artery ligation or suturing, and uterine artery embolization (an interventional procedure) may be considered.
  • Hysterectomy may be necessary if bleeding cannot be controlled or if the risk of bleeding is high due to placenta accreta spectrum or other causes.
• Medications/other:
  • Uterotonics (such as oxytocin) are used for postpartum hemostasis.
  • Transfusion and blood products may be used to control bleeding.
• Lifestyle management:
  • While bleeding is occurring, restrict activities and maintain pelvic rest (remain lying down); prohibit sexual intercourse, intravaginal examinations, and probing.
• Follow-up management:
  • Because the placental location may move upward as pregnancy progresses, confirm it with repeated ultrasound.

3) Checklist before an outpatient visit (items to bring and example questions)

• Items and records:
  • A list of all medications currently being taken (including herbs and supplements).
  • Previous obstetric history (previous cesarean section, uterine surgery, miscarriage, suction curettage, etc.) and the number of times.
  • Results of previous ultrasound examinations and any available images (CD/files).
  • Records related to bleeding: time of onset, pattern (based on tissue or pad usage), color, whether accompanying pain was present, and recurrence pattern.
  • Recent records of changes in weight, blood pressure, and fetal movement.
• Basic checks before the outpatient visit:
  • Confirm the date of the last menstrual period and gestational age.
  • Check for decreased fetal movement and accompanying symptoms such as fever or abdominal pain.
  • Emergency contact information and family history (such as bleeding disorders).
• Items to show the healthcare professionals during the visit:
  • Previous medical records and surgical records (cesarean section records are useful if available).
  • Current medications and allergy information.

4) Examples of general questions to ask the doctor

• "What is the current location and classification of the placenta (complete, partial, marginal, or low-lying)?"
• "What delivery options are available (timing of a planned cesarean section and the plan for emergencies)?"
• "What side effects or risks are associated with treatment (such as the possibility of transfusion, surgery, or hysterectomy)?"
• "What is the prognosis for this pregnancy, and how high is the risk of preterm birth?"
• "What emergency measures should I take at home if bleeding occurs?"

5) Examples of disease-specific questions

• "Are there findings on ultrasound suggestive of placenta accreta spectrum? If it is suspected, what additional tests (detailed ultrasound, MRI) and delivery plan are needed?"
• "My bleeding is recurring. Do you recommend hospital observation or outpatient follow-up? Could you explain the possibility of emergency cesarean section or hysterectomy?"

Additional precautions:

• If vaginal bleeding occurs, immediately contact or visit a medical institution (the emergency room or the obstetrics and gynecology department in charge). Direct intravaginal examination or probing may worsen the bleeding, so avoid it unless instructed by healthcare professionals.
• It is important to have a multidisciplinary team (obstetrics and gynecology, anesthesiology, blood management, intensive care unit, etc.) and sufficient blood prepared in anticipation of massive bleeding during delivery.