Establishing Reference Ranges for Fetal Biometry In Chattogram, Bangladesh

Abstract

Background: Fetal biometry is used in modern obstetrics to precisely estimate gestational age, assess growth and detect anomalies. Nonetheless, different populations may not benefit from international growth charts, such as Hadlock's, which are widely used in Bangladesh. This study aimed to establish local reference ranges for fetal biometric parameters in the Chattogram population of Bangladesh and compare them with the World Health Organization (WHO) international standards.  

Materials and methods: A retrospective chart review of 2,017 ultrasound reports of singleton, non-anomalous pregnancies between 14 and 40 weeks of gestation. Percentile curves for Biparietal Diameter (BPD) Abdominal Circumference (AC) Femur Length (FL) and Estimated Fetal Weight (EFW) were generated and compared with the corresponding WHO International Fetal Growth Standards.

Results: While the median BPD and AC were largely comparable to WHO standards, the local 97.5th percentiles were consistently lower in the later stages of pregnancy. FL measurements, in contrast, were consistently slightly larger than WHO standards. The most significant finding was a distinctive "Crossover" pattern in the EFW charts, with the local 2.5th percentile showing accelerated growth and the 97.5th percentile flattening in the third trimester. Additionally, a 1.35% prevalence of congenital anomalies was detected, with Anencephaly and Multiple anomalies being the most common, each representing 9.30% of the total detected anomalies. 

Conclusion: The findings suggest that a one-size-fits-all approach to fetal growth monitoring is inappropriate for this population. The development and adoption of local reference charts are crucial for improving prenatal care and ensuring better perinatal outcomes in Bangladesh, as international charts may lead to the misclassification of fetal growth abnormalities.

JCMCTA 2026 ; 37 (1) : 17-24