[Multiple pregnancy--ultrasonic biometry after the 28th gestational week--nomograms]

Area of Science:

• Maternal-Fetal Medicine
• Prenatal Ultrasound
• Fetal Biometry

Background:

• Multiple gestation pregnancies present unique challenges in fetal growth assessment.
• Establishing accurate fetal growth parameters is essential for monitoring twin development.
• Existing growth charts may not adequately represent the specific growth patterns of twins.

Purpose of the Study:

• To establish sonographic normograms for key fetal biometric parameters in twins.
• To compare the growth trajectory of twins with that of singleton pregnancies.
• To identify critical gestational windows for monitoring fetal growth in multiple gestations.

Main Methods:

• Development of normograms for biparietal diameter (BPD), femur length (FL), fetal abdominal circumference (FAC), and estimated fetal body weight (EFBW) in multiple gestations.
• Comparative analysis of sonographic indices between twin and singleton pregnancies.
• Assessment of biometric differences between the first and second twins.

Main Results:

• A delayed rate of increase in BPD, FL, and FAC was observed in multiple gestations compared to singletons.
• Specific gestational age cutoffs were identified for these delays: BPD after 26-28 weeks, FL after 34-35 weeks, and FAC after 34-36 weeks.
• Lower estimated fetal body weight (EFBW) was noted after 32-33 weeks, with variations between the first and second twins.

Conclusions:

• Sonographic monitoring of BPD by the 26th week is mandatory for twins.
• Monitoring of FL and FAC by the 34th-35th week is crucial for optimal twin pregnancy management.
• The findings underscore the need for gestation-specific growth charts for twins to ensure accurate assessment and timely intervention.