Intrauterine growth restriction

Disease Description (Causes and Symptoms)

• Definition: This refers to a case in which the estimated fetal weight is below the 10th percentile of the average fetal weight for the gestational age (intrauterine growth restriction, IUGR, or FGR).
• Main causes
  • Maternal factors: chronic nutritional deficiency, smoking, alcohol consumption, medication use, advanced maternal age or very young maternal age, chronic diseases (kidney disease, diabetes, anemia), gestational hypertension, preeclampsia, etc.
  • Placental factors: placental insufficiency (reduced blood flow, placental abnormalities), placental abruption, etc.
  • Fetal factors: chromosomal abnormalities, congenital anomalies, intrauterine infections (e.g., toxoplasmosis and CMV), multiple pregnancy (competition for nutrients).
  • Environmental and social factors: poverty, inadequate nutrition, etc.
• Summary of pathophysiology: Reduced placental blood flow and exchange function are central, resulting in insufficient oxygen and nutrient supply, impaired fetal growth, and metabolic and cardiovascular adaptation (redistribution of blood flow). In severe cases, this can progress to fetal hypoxia, cessation of growth, and cardiovascular failure.
• Main symptoms/signs
  • Clinical: Uterine size smaller than expected for the gestational age (detected during high-risk prenatal care), decreased fetal movement.
  • Test findings: Estimated Fetal Weight on ultrasound at or below the 10th percentile for the same gestational age, decreased amniotic fluid (oligohydramnios), and abnormal umbilical cord or fetal blood flow (Doppler) findings (e.g., absent or reversed end-diastolic flow in the umbilical artery).

Treatment Methods

• General principles: Correct the cause (treat maternal disease, improve nutrition, stop smoking and alcohol consumption), strengthen monitoring of fetal status, and determine the timing and method of delivery for fetal safety.
• Monitoring and diagnostic tests
  • Periodic ultrasound (growth monitoring, amniotic fluid volume), fetal movement counts, nonstress testing (NST), and biophysical profile (BPP).
  • Doppler examination: Assess fetal perfusion status through the umbilical artery, middle cerebral artery, ductus venosus, etc.
• Medication and procedural treatments
  • When preterm delivery is expected (especially <34 weeks): Administer steroids (e.g., betamethasone) for fetal lung maturation.
  • When extremely preterm delivery is expected (usually around 24–32 weeks), consider magnesium sulfate for fetal neuroprotection.
  • Cause-specific treatments, including treatment of maternal hypertension (e.g., labetalol, methyldopa, long-acting extended-release nifedipine), anemia treatment, and infection treatment.
• Delivery plan
  • Determine the timing of delivery based on the overall fetal status (heart rate, Doppler findings, and gestational age). Early delivery, including cesarean section, may be considered in cases of severe blood-flow abnormalities such as reversed umbilical artery flow or abnormal fetal movement or nonstress test results.
  • The method of delivery is determined according to fetal status and the circumstances of labor (vaginal delivery possible vs. cesarean section required).
• Neonatal care: Prepare for neonatal complications such as low birth weight, hypoglycemia, hypothermia, and polycythemia; NICU admission if necessary.
• Lifestyle management and precautions for the mother
  • Avoid smoking and alcohol, maintain adequate nutritional intake (protein and calorie supplementation), get sufficient rest, and undergo regular prenatal examinations and fetal movement monitoring.
  • Strictly follow the prescribed medication and testing schedules, and visit the hospital immediately if symptoms such as decreased fetal movement, abdominal pain, or bleeding occur.

Checklist Before an Outpatient Visit (Including Suggested Items to Bring and Example Questions)

• Items to bring (recommended)
  • List of currently used medications and supplements (medication name, dose, and time of administration)
  • Results of previous prenatal examinations, ultrasounds, and blood tests (printouts or photos if possible)
  • Records of weight and blood pressure (during the interval since the most recent appointment), and fetal movement count records (if available)
  • Lifestyle information (smoking, alcohol consumption, occupational risk factors)
• Recommended self-monitoring before the visit
  • Record the number of fetal movements per day (contact the hospital immediately if there is a significant decrease)
  • Record dietary intake and weight changes
• Example questions (to show the doctor)
  • "What is the estimated fetal weight on this ultrasound, and where is it positioned on the growth curve?"
  • "What does the Doppler test result mean? Are additional tests needed?"
  • "How likely is it that delivery will need to be moved earlier?"

Examples of General Questions to Ask the Doctor

• "What is the prognosis for this condition, both short-term and long-term?"
• "What tests are recommended, and how often should they be performed?"
• "What are the side effects and precautions for the medications I may be prescribed?"
• "What specifically should I change in my lifestyle, such as nutrition, exercise, and rest?"

Examples of Condition-Specific Questions

• "Is the fetal growth on ultrasound symmetrical (is the fetus small overall) or asymmetrical (is the abdomen mainly small)? How does this difference affect treatment or prognosis?"
• "An end-diastolic flow abnormality (absent or reversed flow) was observed in the umbilical artery on the Doppler examination. What criteria are used to determine how this affects the decision about delivery?"