Diagnostic Accuracy of Ultrasound Scanning In In-Utero Prediction of Fetal Gender

Abstract

Background: Until recently, the ultrasound was the only non-invasive scientific way to learn the gender of the unborn baby. In developed countries, ultrasound practice has far been in existence for decades. However, in developing world, the advent of ultrasound was in the last three decades in majority of the centres. Thus gender assessment using ultrasound is an expertise that was acquired in the developing world in less than three decades in generality of cases. Objectives: This was to determine the accuracy of ultrasound in predicting the sex of baby in-utero. Methods: This study was conducted in Nnamdi Azikiwe University Teaching Hospital, and Life Specialist Hospital, both in Nnewi, south-east Nigeria. The accuracy of the ultrasound was related to the gestational age at which the ultrasound was done, body mass index (BMI), the presentation of the fetus and the experience of the Sonographer. The ultrasound scans were done by a Registrar in department of Obstetrics, a consultant in the same department and a consultant radiologist. Analysis was done using SPSS Package version [19]. Results: Three hundred and fifty one cases met the inclusion criteria and were finally used for analysis. This study revealed that the overall accuracy was 96%. In all, 14 cases were misdiagnosed out of 351 cases. Further analysis showed that 100% accuracy was obtained by the scans done by the consultants but 88.0% by the ones done by the registrar. Apart from experience, the BMI and presentation of the fetuses were contributory to the high accuracy. In patients with body mass index (BMI) <25 kg/m2 , the accuracy was 98.1% and 72.7% for cephalic and breech presenting fetuses respectively (p>0.05). Similarly, in patients with BMI of ≥25 but <30 kg/m2 , the accuracy was 93.3% and 66.7% for cephalic and breech presenting fetuses respectively. This too was not statistically significant (p>0.05). There was also no statistical significant difference in the accuracy of fetal sex determination between the two groups of women with respect to their BMI (p>0.05). None of the fetuses were in transverse lie and none had malformations of the external genitalia on delivery. Conclusion: Ultrasound remains a very important tool in the prediction of the sex of the fetus especially in developing country setting where there is high penchant for male babies. A good number of factors contribute to this accuracy