[Mean fetal growth curve adjustment]

Area of Science:

• Obstetrics and Gynecology
• Neonatology
• Biostatistics

Context:

• Accurate fetal growth assessment is crucial for monitoring fetal well-being and identifying potential growth abnormalities.
• Existing fetal growth curves may not fully capture the complex, sex-specific patterns of growth across gestation.

Purpose:

• To establish an optimal logistic equation for anthropometric fetal growth curves (weight, height, head circumference) stratified by sex and gestational age.
• To identify the inflection point of these curves, indicating the period of maximum growth velocity.
• To provide precise reference data for clinical use in neonatal care.

Summary:

• A logistic curve model accurately describes fetal anthropometric growth (weight, height, head circumference) in 25,200 newborns (25-43 weeks gestation) using non-linear regression.
• Reference tables for mean growth and upper/lower limits are provided for both sexes from 25 to 43 gestational weeks.
• The study identified that mean growth velocity slows earlier in female fetuses compared to males.

Impact:

• Provides a validated, sex-specific logistic growth model for enhanced fetal growth monitoring.
• Offers precise data to aid clinicians in identifying deviations from optimal fetal growth trajectories.
• Contributes to a better understanding of sex-dimorphic growth patterns in late gestation.