Growth patterns in fetuses with isolated cardiac defects.

Area of Science:

• Prenatal diagnosis
• Fetal medicine
• Pediatric cardiology

Background:

• Congenital heart defects (CHDs) can impact fetal development.
• Longitudinal growth data for parameters beyond head circumference in fetuses with CHDs are limited.

Purpose of the Study:

• To assess longitudinal growth patterns of fetal biometry, including abdominal circumference (AC) and femur length (FL), in fetuses with isolated CHDs diagnosed prenatally.
• To analyze growth differences across various categories of isolated CHDs.

Main Methods:

• Retrospective study of 246 live births with isolated CHDs diagnosed prenatally.
• Fetal biometry parameters (head circumference [HC], AC, FL) assessed at multiple time points (18-35 weeks' gestation).
• Linear mixed modeling used to construct growth models and analyze repeated measurements, with parameters transformed into Z scores.

Main Results:

• A modest but significant linear decrease in head circumference (HC) growth was observed in the second half of pregnancy for fetuses with CHDs.
• Abdominal circumference (AC) and femur length (FL) growth trajectories were not significantly affected.
• Fetal growth modeling predicted a significantly smaller HC at 36 weeks' gestation specifically in fetuses with conotruncal heart defects.

Conclusions:

• Fetuses with CHDs exhibit a significant, albeit modest, linear decrease in HC growth during gestation.
• Growth patterns for AC and FL remain stable in fetuses with isolated CHDs.
• Specific CHD types, such as conotruncal defects, may be associated with more pronounced effects on fetal head growth.