VALUE OF STANDARDIZED GESTATIONAL-AGE CHARTS FOR FETUSES OF 1ST-GENERATION ORIENTAL IMMIGRANTS TO CANADA

OBJECTIVE: To ascertain if standard gestational age charts can be used to accurately predict the gestational age of fetuses of first-generat ion Oriental immigrants to Canada. PATIENTS AND METHODS: Over a 3-year period, all patients presenting for obstetric ultrasound examinations were invited to participate in the study. The authors recorded bipari etal diameter, head circumference, femur length and abdominal circumfe rence for 139 fetuses in the second and third trimesters. A study perf ormed in the first trimester was used as the baseline for gestational age. The data for 126 of the fetuses were complete, and these data wer e used for the analysis. RESULTS: For 77 of the fetuses, both parents were Oriental, and for 49, one or both parents were not Oriental; the latter constituted the control group. A total of 1008 individual measu rements were obtained, and of these, all but 14 fell within two standa rd deviations of the norm, according to standard gestational age chart s. Of the abnormal measurements, seven were obtained from five fetuses with Oriental parents, and seven were obtained from six fetuses in th e control group. The difference between the two groups in the proporti on of measurements falling either above or below two standard deviatio ns from the norm was not statistically significant (Fisher's exact tes t, p = 0.41694). CONCLUSION: The authors conclude that standard gestat ional age charts can be used to determine gestational age in first-gen eration Oriental immigrants to Canada.