Premature rupture of membranes

Disease Description (Causes and Symptoms)

• Definition: A condition in which the amniotic sac ruptures before the onset of labor (uterine contractions). When it occurs before 37 weeks of pregnancy, it is classified as preterm premature rupture of membranes (PPROM), and the risk of neonatal and maternal complications increases.
• Main pathophysiology: Rupture of the amniotic sac is associated with infection and inflammatory responses (bacterial infection → activation of inflammatory mediators and matrix metalloproteinases) and structural weakening of the uterus and amniotic sac (oxidative stress, cellular senescence, collagen breakdown, etc.).
• Common causes/risk factors: Vaginal infections (such as bacterial vaginosis), a history of PROM, multiple pregnancy, cervical insufficiency, preterm uterine contractions and uterine overdistension, smoking, low body weight and nutritional deficiencies, trauma, and invasive procedures (such as amniocentesis).
• Symptoms: Sudden leakage of warm, watery vaginal fluid (watery discharge), a large amount of fluid leaking at once (“gush”), and odor (a foul odor in cases of infection). Uterine contractions (labor) may occur before or after diagnosis. Signs of fetal risk: decreased fetal movement and abnormal fetal heart rate.

Treatment

• Diagnostic principles: Confirmation at a hospital through sterile speculum examination (observation of pooling), the nitrazine (pH) test, the fern test, specific tests (IGFBP-1- or PAMG-1-based AmniSure/ROM Plus), and ultrasound (amniotic fluid index, AFI). Because nitrazine and fern tests may produce false-positive or false-negative results, they should be interpreted together with the clinical findings.
• Management principles (the main criteria are gestational age and the presence or absence of signs of infection)
  • 37 weeks or later (term PROM): Labor induction is generally performed to reduce the risk of infection (induction within 24 hours is usually recommended). Antibiotics are determined according to the individual situation and GBS status.
  • 34+0 to 36+6 weeks: Practices vary by institution and situation. In most cases, a choice is made between labor induction and antibiotics with observation. Follow the opinion of the attending obstetrician.
  • <34 weeks (preterm PPROM): Expectant management (inpatient observation) + latency therapy
    • Antibiotics (latency antibiotics): If following ACOG recommendations (example), switch from IV ampicillin + erythromycin after 48 hours to oral amoxicillin + erythromycin (for a total of 7 days); the medications and dosages may differ according to institutional recommendations. Purpose: to delay delivery and reduce the risk of infection.
    • Administration of betamethasone (or dexamethasone) to promote fetal lung maturation (generally recommended at 24–34 weeks).
    • Magnesium sulfate: Considered before 32 weeks for neuroprotection (reducing the risk of intraventricular hemorrhage).
    • GBS (group B streptococcus) prophylaxis: If the mother’s GBS status is positive or unknown, antibiotics (usually penicillin) are administered during delivery.
    • Tocolytics: Generally contraindicated when infection is suspected. They may be considered on a limited basis for a short period (e.g., the short period needed to administer steroids).
• Emergency and initial precautions: If umbilical cord prolapse is suspected, immediate delivery (such as cesarean section) is necessary. If infection is suspected (foul-smelling discharge, fever, increased fetal heart rate, uterine tenderness), immediate delivery should be considered and broad-spectrum antibiotics should be administered.
• Other conservative and supportive treatment: Inpatient observation, monitoring of vital signs, body temperature, blood tests, and the fetus; minimizing digital vaginal examinations (which increase the risk of infection); and lifestyle instructions such as abstinence and avoiding bathtub baths.

Checkpoints Before an Outpatient Visit (Including Items to Prepare, Records, and Example Questions)

• Items to prepare (bring to the hospital)
  • A list of all medications and supplements currently being taken
  • Results of pregnancy-related tests (including reports, if possible)
  • A record of recent changes in fetal movement (the most recent time decreased fetal movement was noticed)
  • The time symptoms began (when fluid first appeared), amount (a large amount at once or a small amount continuously), color (clear, bloody, or yellow-green), and whether there is an odor
  • Records of fever, abdominal pain, changes in vaginal discharge, and whether labor contractions are present
• Items to check yourself before the visit (so that you can explain them directly to the doctor during the outpatient visit)
  • When did the amniotic fluid begin to leak, and what was its pattern?
  • Have you recently had fever, chills, abdominal pain, or decreased fetal movement?
  • Do you have a GBS test result? (If so, what was the result?)
  • Do you have a history of premature rupture of membranes or preterm birth?
• Items for the medical staff to check during the visit
  • Gestational age (exact obstetric history), fetal position (whether the fetus is in a head-down position), and whether uterine contractions are currently present
  • Signs of infection (maternal body temperature, blood tests such as CRP), and amniotic fluid volume (ultrasound AFI)

General Example Questions to Ask the Doctor

• “What treatment is recommended at my current gestational age? Do I need to deliver immediately, or can we observe the situation?”
• “How high is the risk of infection and fetal complications in this situation?”
• “Which antibiotics and steroids will be administered, and what are their side effects?”
• “What should I be careful about at home before delivery (activities, meals, sexual activity, etc.)?”

Examples of Condition-Specific Questions

• (If pregnancy is <34 weeks) “Do you recommend administering steroids and magnesium? After administration, how long might delivery potentially be delayed?”
• (If GBS status is unknown or positive) “When will GBS prophylactic antibiotics be started during delivery, and which medication will be used? How will management differ if the amniotic fluid has been leaking for more than 18 hours?”

Summary of Precautions

• If rupture of the amniotic sac is suspected, visit a medical institution immediately. While waiting at home, do not insert fingers or objects into the vagina, and avoid sexual intercourse and bathtub baths. If fever, foul-smelling discharge, decreased fetal movement, severe abdominal pain, or bleeding occurs, go to the emergency room immediately.

The prognosis varies greatly depending on gestational age and the presence or absence of infection. The earlier it occurs, the greater the risk of neonatal complications such as respiratory distress syndrome, infection, and intestinal or brain hemorrhage.