Effect of head circumference in combination with facial profile line on ultrasonic diagnosis of microcephaly.

Objective

Recently, microcephaly has usually been misdiagnosed only by ultrasound via measurement of head circumference (HC). Therefore, the aim of this study is to find another diagnostic index to supplement the original diagnostic method of microcephaly, to improve the detection rate of fetal microcephaly and to reduce the misdiagnosis rate.

Methods

We retrospectively analyzed 123 pregnant women from February 2012 to January 2017 with fetal HC less than two standard deviations (SD). The facial profile line (FPL) was determined by ultrasonography. The first method (M1) was only used HC to determine whether the fetus was microcephaly, the second one (M2) was to combine HC and FPL for the diagnosis of microcephaly. Results were classified into five orderly categories by experienced sonographers. ROC curve was drawn to evaluate the diagnostic effect.

Results

Among the pregnant women, 14 cases of fetal head circumference were less than 3SD, 109 were -2SD < HC≤ -3SD. A total of 12 cases were confirmed of microcephaly by magnetic resonance imaging (MRI) or postnatal, 10 cases of HC were less than 3SD, 2 were -2SD < HC≤ -3SD. The area under the ROC curve for M1 and M2 were 0.751 and 0.983 respectively.

Conclusion

The HC in combination with FPL can be used to evaluate the fetal HC and forehead development quickly, and to improve the sensitivity and specificity of diagnosing fetal microcephaly.