The correlation between gestational age and the length of the clavicle

Objective 

To evaluate correlation between gestational week and fetal clavicle length (CL) until 27 week's gestation.

Methods 

This study was cross-sectional study of patients between 14 and 27 weeks’ gestation. Inclusion criteria was well-established dates (confirmed with early ultrasound), singleton, non-anomalous fetuses, and intact amniotic membranes with enough amniotic fluid. Sonographic measurements such as biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL), estimated fetal weight (EFW), clavicle lenght (CL) and cerebellum diameter. Pearson’s correlation and P-values for the relationships between CL and other biometry measurements were estimated.

Results 

We evaluated 77 patients in our clinic. All attempts assessing the CL were successful. Mean maternal age was 29.11 ± 5.85 years, median gravidity 3 (range 0–10), and median parity 2 (range 0–5). Fetal CL, BPD, HC, AC, HL, FL, fetal weight and cerebellum diameter were correlated significantly and strongly with gestational week and also Pearson correlation values were 0.965, 0.951, 0.917, 0.964, 0.959, 0.965, 0.925 and 0,954, respectively (all p < 0.01).

Conclusion

We suggest that the clavicula diameter as millimetres by ultrasonography was found significantly positive correlation with gestational weeks. We suggest the 1 mm = 1 week rule should be used because of anomaly of cerebellum and vermis and also for patients had unknown last menstrual day. The lenght of clavicula may use to detect gestational week.

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