Should we use customized fetal growth percentiles in urban Canada?

Area of Science:

• Maternal-Fetal Medicine
• Prenatal Diagnostics
• Fetal Growth Assessment

Background:

• Accurate antenatal diagnosis of fetal growth is essential for optimal pregnancy outcomes.
• Distinguishing between constitutionally small fetuses and those with pathological intrauterine growth restriction (IUGR) presents a significant clinical challenge.
• Current methods may lead to misclassification, impacting management strategies.

Purpose of the Study:

• To evaluate the utility of customized fetal growth percentiles in differentiating true IUGR from constitutional small for gestational age (SGA) fetuses.
• To assess the impact of implementing ethnicity-specific birth weight curves on SGA and large for gestational age (LGA) classifications in multi-ethnic urban settings.
• To determine the potential benefits of customized percentiles for minority populations.

Main Methods:

• Review of evidence supporting the use of customized growth percentiles in fetal assessment.
• Analysis of projected changes in SGA and LGA rates using customized versus standard charts.
• Modeling the effects on diagnostic accuracy in diverse populations, using Toronto as a case study.

Main Results:

• Customized growth percentiles offer a more accurate method for distinguishing pathological IUGR from constitutional SGA.
• Adoption of ethnicity-specific curves is projected to significantly decrease false-positive SGA diagnoses among visible minorities.
• These adjustments are also expected to improve the detection rates of true LGA fetuses in these populations.

Conclusions:

• Customized fetal growth percentiles are a valuable tool for improving the accuracy of fetal growth assessment.
• Implementing ethnicity-specific standards can reduce diagnostic disparities in multi-ethnic populations.
• This approach enhances the detection of both growth restriction and macrosomia, leading to more appropriate antenatal care.