Post-term infant

Disease Description (Causes and Symptoms)

• Definition: A newborn with a gestational age of 42 weeks (≥294 days) or more (post-term infant).
• Causes/pathophysiology: No clear single cause is known. Advanced maternal age, multiparity, and maternal diabetes may increase the risk. If the fetus remains in the uterus for a prolonged period, placental function may gradually decline, potentially causing fetal hypoxia and inadequate nutrient supply (placental insufficiency). This may lead to decreased fetal activity, reduced amniotic fluid volume (oligohydramnios), and an increased likelihood of meconium passage.
• Main symptoms and physical findings (newborn): Reduced lanugo and vernix caseosa, long fingernails and toenails, abundant hair, pale, parchment-like, peeling skin, and well-defined facial features. Abnormal fetal heart rate and meconium staining (with a risk of meconium aspiration) may occur.
• Pathophysiology related to complications: Placental insufficiency → chronic hypoxia → fetal stress (abnormal fetal heart rate), meconium passage → meconium aspiration pneumonia, hypoxic brain injury during delivery (HIE in severe cases), prolonged labor, shoulder dystocia, birth trauma, neonatal hypoglycemia, polycythemia, and others.

Treatment Methods

• Obstetric management (before delivery):
  • Fetal assessment: Fetal oxygenation and amniotic fluid status are evaluated using a nonstress test (NST), ultrasound (amniotic fluid volume and biophysical index), biophysical profile (BPP), Doppler studies, and other methods.
  • Delivery planning: Around 41 weeks, after an individualized risk assessment, induction of labor (prostaglandins, membrane sweeping/artificial rupture of membranes, or oxytocin induction according to cervical ripeness) or cesarean section may be considered. Cesarean section is recommended in cases of fetal distress, failed induction, or an abnormal fetal heart rate.
• Initial neonatal care:
  • If meconium aspiration is suspected immediately after birth, airway management and suctioning are performed (including endotracheal suctioning and mechanical ventilation if necessary).
  • In cases of respiratory distress, oxygen is provided along with assisted ventilation or mechanical ventilation; endotracheal intubation and extracorporeal membrane oxygenation may be used if necessary (in severe cases).
  • If hypoxic-ischemic encephalopathy is suspected, follow neurological treatment guidelines, including therapeutic hypothermia when selectively indicated.
  • Rapid evaluation and management of neonatal hypoglycemia, dehydration, hypothermia, polycythemia, and other conditions (blood glucose measurement, fluid therapy, and close monitoring).
• Medications/procedures: Oxytocin and prostaglandins (labor induction), cesarean section, neonatal respiratory support and antibiotics (when pneumonia is suspected), and medications for fluid and blood glucose control.
• Lifestyle management and precautions: Visit the hospital immediately if fetal movement decreases after the expected delivery date, regularly monitor fetal movement, and inform medical staff of prenatal test results and previous delivery history (including whether a cesarean section was performed).

Outpatient Visit Checkpoints (Including Examples of Preparation and Questions)

• Items/documents to bring:
  • A list of currently used medications (including prescriptions, OTC medications, and herbal medicines)
  • Previous prenatal test results (ultrasound, GBS, blood glucose testing, etc.) and the recorded expected delivery date
  • Records of previous pregnancies and deliveries (whether a previous cesarean section was performed and any history of difficult labor)
  • Records of fetal movement (changes in the number of movements per day), and records of fever, amniotic fluid leakage, or bleeding
• Materials to show the doctor during the outpatient visit:
  • Recent ultrasound images/reports and NST or BPP results (if available)
• Things to check personally during the outpatient visit:
  • Whether fetal movement has decreased (daily fetal movement monitoring)
  • Whether fever, vaginal bleeding, amniotic fluid leakage, or abdominal pain is present
• Example questions (phrases the patient can prepare in advance):
  • "Fetal movement has recently decreased compared with usual. When should I come to the hospital?"
  • "Do you recommend labor induction? What are the methods and risks?"

Examples of General Questions to Ask the Doctor

• What are the side effects of this medication (or treatment), and what is the expected recovery period?
• What is the likelihood of conversion to a cesarean section during induced labor or spontaneous labor?
• If an abnormality is found in the fetal status (heart rate, amniotic fluid, Doppler findings, etc.), when is an immediate cesarean section necessary?
• What tests will be performed on the newborn immediately after birth? (Blood glucose, oxygen saturation, blood tests, etc.)

Examples of Disease-Specific Questions

• I am currently 41 weeks pregnant. Given my situation (cervical ripeness, diabetes, etc.), do you recommend labor induction? If so, what method will be used to begin it?
• If signs of reduced placental function or meconium passage (reduced amniotic fluid or an abnormal fetal heart rate) appear, how will you change the delivery plan?

Note: Because delivery and neonatal care vary according to the individual patient's circumstances (fetal status, maternal underlying diseases, medical history, etc.), decisions should be made based on an evaluation by the attending physician.