Related Experiment Video
Updated: Apr 8, 2026
Human Fetal Blood Flow Quantification with Magnetic Resonance Imaging and Motion Compensation
Published on: January 7, 2021
Unconditional and conditional standards for fetal abdominal circumference and estimated fetal weight in an ethnic
Ying Xu1, Ngee Lek2,3, Yin Bun Cheung4,5
1Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore. tinayxu@gmail.com.
Insights
New fetal growth charts for abdominal circumference and estimated fetal weight (EFW) are now available for ethnic Chinese populations. These standards aid in diagnosing fetal growth restriction and predicting small-for-gestation age.
Area of Science:
- Obstetrics and Gynecology
- Fetal Medicine
- Biometry
Background:
- Accurate diagnosis of intrauterine fetal growth restriction and prediction of small-for-gestation age are crucial in prenatal care.
- Current diagnostic methods often rely on fetal abdominal circumference and estimated fetal weight (EFW).
Purpose of the Study:
- To develop unconditional (cross-sectional) and conditional (longitudinal) growth standards for fetal abdominal circumference and EFW.
- To provide population-specific standards for an ethnic Chinese population.
Main Methods:
- Utilized data from the Growing Up in Singapore Towards healthy Outcome (GUSTO) birth cohort study.
- Included singleton pregnancies with healthy profiles, obtaining biometric measurements via ultrasound.
- Employed the Hadlock algorithm for EFW calculation and mixed-effects models for standard development.
Main Results:
- Established growth trajectories for fetal abdominal circumference (linear) and EFW (accelerating) from 18 to 36 weeks gestation.
- Observed gender differences, particularly in lower percentiles (10th).
- This population's growth trajectories started lower but normalized at later gestations compared to existing charts.
Conclusions:
- Developed and validated unconditional and conditional standards for fetal abdominal circumference and EFW in an ethnic Chinese population.
- Provided electronic spreadsheets for easy implementation of these new growth standards.
- These standards facilitate improved monitoring of fetal size and growth, aiding in the management of fetal growth abnormalities.
Background:
Diagnosis of intrauterine fetal growth restriction and prediction of small-for-gestation age are often based on fetal abdominal circumference or estimated fetal weight (EFW). The present study aims to create unconditional (cross-sectional) and conditional (longitudinal) standards of fetal abdominal circumference and EFW for use in an ethnic Chinese population.
Methods:
In the Growing Up in Singapore Towards healthy Outcome (GUSTO) birth cohort study in Singapore, fetal biometric measurements were obtained at enrolment to antenatal care (11-12 weeks) and up to three more time points during pregnancy. Singleton pregnancies with a healthy profile defined by maternal, pregnancy and fetal characteristics and birth outcomes were selected for this analysis. The Hadlock algorithm was used to calculate EFW. Mixed effects model was used to establish unconditional and conditional standards in z-scores and percentiles for both genders pooled and for each gender separately.
Results:
A total of 313 women were included, of whom 294 had 3 and 19 had 2 ultrasound scans other than the gestational age dating scan. Fetal abdominal circumference showed a roughly linear trajectory from 18 to 36 weeks of gestation, while EFW showed an accelerating trajectory. Gender differences were more pronounced in the 10(th) percentile than the 50(th) or 90(th) percentiles. As compared to other published charts, this population showed growth trajectories that started low but caught up at later gestations.
Conclusions:
Unconditional and conditional standards for monitoring fetal size and fetal growth in terms of abdominal circumference and EFW are available for this ethnic-Chinese population. Electronic spreadsheets are provided for their implementation.
