Preterm birth

Disease Description (Causes and Symptoms)

• Definition: Premature birth is a condition in which a baby is born at 20 weeks or more but before 37 weeks of pregnancy. Depending on the cause and pathophysiology, it is classified as spontaneous preterm birth (preterm labor or preterm premature rupture of membranes) and indicated delivery induced or performed by cesarean section for medical reasons (e.g., severe preeclampsia, placental abruption, etc.).
• Main causes: A history of previous preterm birth, smoking (active or passive), multiple pregnancy, uterine or cervical abnormalities or cervical insufficiency, cervical shortening (short cervix), intrauterine infection (bacterial vaginosis, urinary tract infection, etc.), gestational hypertension/preeclampsia and placental abnormalities, severe stress and inadequate nutrition, etc. Priority information from RAG: Smoking increases the risk of premature rupture of membranes by 2–5 times and the risk of preterm birth by 1.2–2 times; secondhand smoke exposure also increases the risk.
• Pathophysiology (briefly): Infection or inflammation → increased substances that trigger uterine contractions (such as prostaglandins) → uterine contractions and cervical changes → preterm delivery. Premature rupture of membranes can trigger preterm birth through infection and preterm labor.
• Symptoms: Regular uterine contractions (increasing frequency and intensity), pelvic or lower abdominal pressure or cramps, pain similar to menstrual cramps, abnormal vaginal bleeding, increased small amounts of mucous or watery discharge (amniotic fluid leakage if the membranes have ruptured), and decreased fetal movement (when the fetus is under stress).

Treatment and Precautions (Complications and Self-Care)

• Hospitalization and monitoring: If there is severe labor pain, rupture of membranes, bleeding, or periodic contractions, hospitalization is required for fetal heart rate monitoring (NST), uterine contraction monitoring, and ultrasound examinations (gestational age, cervical length, and amniotic fluid volume).
• Promoting fetal lung maturation: Between 24 and 34 weeks of pregnancy (depending on guidelines and circumstances), antenatal corticosteroids such as betamethasone or dexamethasone are administered according to standard doses and schedules to reduce neonatal respiratory distress.
• Neuroprotection: When delivery before 32 weeks is anticipated, magnesium sulfate may help reduce the risk of cerebral palsy.
• Tocolytics: These are used to delay delivery (e.g., oral nifedipine, atosiban, etc.). However, tocolytics are used only for a short period to allow time for steroid administration or preparation for delivery rather than for long-term benefits. Some medications, such as terbutaline, are recommended only for limited use.
• Antibiotics: When there is preterm premature rupture of membranes (PPROM) or suspected infection, latency antibiotic therapy may be given, along with antibiotics during delivery to prevent group B Streptococcus (GBS) infection. (Follow the attending physician’s instructions regarding specific medications and doses.)
• Preventive and selective treatment: In people with a history of spontaneous preterm birth and/or a short cervix, progesterone (vaginal progesterone or, depending on history, consideration of 17-OHPC) or cervical cerclage (with strict timing and indications) may reduce the risk of recurrence. Consultation with medical professionals is necessary.
• Neonatal care: Premature infants require intensive care in the NICU to manage body temperature, breathing, nutrition, and infection. Complications that occur more frequently include neonatal respiratory distress syndrome (RDS), bronchopulmonary injury (chronic lung disease), cerebral hemorrhage and cerebral palsy, necrotizing enterocolitis (NEC), infection, and growth and developmental delays.
• Lifestyle management and precautions: Strictly avoid smoking (including secondhand smoke exposure), immediately report symptoms of infection (fever or changes in vaginal discharge), attend regular prenatal checkups, avoid excessive physical work and stress, and manage weight gain and nutrition.
• Prognosis in one line: The prognosis of premature infants is greatly influenced by gestational age and birth weight; the lower the gestational age, the higher the risk of short- and long-term complications (survival rates have improved with advances in intensive care).

Checklist Before an Outpatient Visit (Items to Bring, Records, and Sample Questions)

• Items to prepare:
  • List of currently taken medications and supplements (including doses and administration times)
  • Previous pregnancy and delivery history (especially whether there was a previous preterm birth and when it occurred)
  • Recent prenatal examination, ultrasound, and test results (copies if possible)
  • Symptom record: time labor pain began, interval and duration, intensity, vaginal discharge (amount, color, and odor), whether there is bleeding, and changes in fetal movement
  • Smoking status (self, family members, or cohabitants), workplace environment (exposure to smoking), and stress factors
  • Allergies and underlying conditions (hypertension, diabetes, etc.)
• Key information to tell the medical staff during the outpatient visit:
  • When the symptoms began (time and number of days)
  • Contraction intervals (e.g., occurring every 10 minutes for more than 1 hour)
  • Whether fluid is flowing (suspected rupture of membranes); if it is difficult to determine whether it is urine or amniotic fluid, immediate testing is necessary
  • Gestational age at previous delivery and the newborn’s condition (e.g., whether NICU admission was required)

General Sample Questions to Ask the Doctor

• "At my current gestational age, do I need treatment to delay delivery, such as steroids or tocolytics? What is the reason?"
• "What are the side effects of this medication (steroids, nifedipine, magnesium, etc.), and what potential risks could it pose to the mother and baby?"
• "What preventive measures, such as progesterone or cervical cerclage, do you recommend to reduce the risk of preterm birth in this pregnancy?"
• "What is the level of our hospital’s NICU, and what treatments can be expected for the newborn?"

Examples of Condition-Specific Questions

• "What is the length of my cervix in millimeters on ultrasound? Depending on this value, what treatment is needed, such as vaginal progesterone or cerclage?"
• "If preterm premature rupture of membranes is suspected (or confirmed), do I need to be hospitalized immediately? What is the plan for antibiotics and steroid administration?"

Note: The information provided is general medical information. Diagnosis and treatment based on an individual’s condition should be determined in consultation with the attending obstetrician-gynecologist.