Nomogram for Fetal Limb Bones in Chinese Ethnicity

Abstract Description

Proposed Topic (Most preferred): :

Research and Innovations (new projects / technology / innovations / service models)

Authors (including presenting author) :

Lee HYD(1), Shu W(1), Choi KY(2), Chan LW(1)

Affiliation :

(1) Department of Obstetrics & Gynaecology, Pamela Youde Nethersole Eastern Hospital, (2) Chinese Language Education and Assessment Centre, Lingnan University

Introduction :

Ethnic-specific nomograms for fetal biometry is important for diagnosing fetal growth restriction and fetal anomalies, such as skeletal dysplasia.

Objectives :

To construct fetal limb bone nomograms in the Chinese ethnic population.

Methodology :

This was a prospective cross-sectional study on singleton pregnancies between 12 to 37 weeks of gestation. Femur, tibia, fibula, humerus, ulna, radius and foot length were measured in a standardized manner by one of the three sonographers. Each fetus’s measurements were only included once and those who developed maternal or fetal complications were excluded. Fractional polynomial regression model was used to obtain 3rd, 10th, 50th, 90th and 97th centiles for each of the limb measurements. Z-score for the 50th centile of each fetal limb measurement was then compared with published nomograms from other populations.

Result & Outcome :

Results:

Of the 843 scans performed, 775 were included in analysis after excluding conditions such as pre-eclampsia, chromosomal abnormalities, single umbilical artery and skeletal dysplasia. Comparison with other populations shows that Chinese had shorter fetal limb bone lengths than the Caucasian and Afro-Caribbean populations.

Conclusion:

This study established nomograms for all the fetal limb bones in the Chinese ethnic population, which showed lengths comparatively shorter than Caucasian and Afro-Caribbean nomograms. This would reduce the false alarm of short fetal limb bone lengths and its consequent anxiety and intervention.