Growth patterns of the humeral and femur length in a multiethnic population

OBJECTIVES: To study whether there are any differences in growth of the femoral and humeral length between the three major ethnic groups in Malaysia viz Malays, Chinese and Indians. The effect on fetal growth by gender of the baby and parity of the mother was also studied.

METHODS: The setting was the University of Kuala Lumpur. Thirty-four Malay, 35 Chinese and 34 Indian normal pregnant middle-class women were studied longitudinally by monthly ultrasound scans for 18 to 38 weeks of gestation. The data were subjected to regression analysis; the quadratic curve was found to be the most adequate. Dummy variables were used to determine any effects by gender, parity as well as ethnicity on the length of limb growth. There was no difference in birth weights of the three ethnic groups studied, nor in gender or parity.

RESULTS: There were found to be significant differences in limb lengths of the Indians (longer) when compared with the Malays and Chinese. Parity seems to affect only Indians in whom the multiparous fetuses have shorter limb lengths than the primaparous. There appears to be no effect by gender.

CONCLUSION: There appear to be definite differences in growth of limb length between the different Malaysian ethnic groups and this should be taken into account when growth charts are used and when fetal weight formulas are calculated using limb lengths. The limitation of this study was that the numbers of subjects studied were small. Larger studies will be able to confirm or refute the findings.