Value and Diagnostic Efficacy of Fetal Morphology Assessment Using Ultrasound in a Poor-Resource Setting

Abstract

Background: Ultrasound is operator-dependent, and its value and efficacy in fetal morphology assessment in a low-resource setting is poorly understood. We assessed the value and efficacy of fetal morphology ultrasound assessment in a Nigerian setting. Materials and Methods: We surveyed fetal morphology ultrasound performed across five facilities and followed-up each fetus to ascertain the outcome. Fetuses were surveyed in the second trimester (18th–22nd weeks) using the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guideline. Clinical and surgical reports were used as references to assess the diagnostic efficacy of ultrasound in livebirths, and autopsy reports to confirm anomalies in terminated pregnancies, spontaneous abortions, intrauterine fetal deaths, and still births. We calculated sensitivity, specificity, positive and negative predictive values, Area under the curve (AUC), Youden index, likelihood ratios, and post-test probabilities. Results: In total, 6520 fetuses of women aged 15–46 years (mean = 31.7 years) were surveyed. The overall sensitivity, specificity, and AUC were 77.1 (95% CI: 68–84.6), 99.5 (95% CI: 99.3–99.7), and 88.3 (95% CI: 83.7–92.2), respectively. Other performance metrics were: positive predictive value, 72.4 (95% CI: 64.7–79.0), negative predictive value, 99.6 (95% CI: 99.5–99.7), and Youden index (77.1%). Abnormality prevalence was 1.67% (95% CI: 1.37–2.01), and the positive and negative likelihood ratios were 254 (95% CI: 107.7–221.4) and 0.23 (95% CI: 0.16–0.33), respectively. The post-test probability for positive test was 72% (95% CI: 65–79). Conclusion: Fetal morphology assessment is valuable in a poor economics setting, however, the variation in the diagnostic efficacy across facilities and the limitations associated with the detection of circulatory system anomalies need to be addressed.

Prevalence of congenital anomalies in Sudanese fetuses: A prospective study

“…These results fall in line with Anderson et al (1995) who proposed that the CNS was reported in 92% of the CAs and Singh et al (2006) who concluded that the common anomaly was ventriculomegaly 27.33% followed by anencephaly 26.00%. Although other authors (Ukweh et al, 2019) stated that a majority (35%) of the detected CAs were related to the central nervous system followed by digestive (12.8%) and genitourinary (11.9%) systems.…”

“…Onyambu and Tharamba (2018) showed that the prevalence of CAs through routine U/S was 3%. Ukweh et al (2019) concluded that anomaly prevalence is 1.67%. Neto et al (2009) indicated a very high prevalence of CAs; they stated that the prenatal ultrasonography diagnosed congenital anomalies presented in 63.2%, among this 56.2% were confirmed after birth.…”

What do radiologists look for? Advances and limitations of perceptual learning in radiologic search

“…“Scanning errors” (also called “search errors”) result from failures in the first stage of search. Specifically, peripheral information fails to guide the observer's gaze to a relevant location, and high-resolution foveal vision does not assist interpretation because the observer never looks at the location directly ( Doshi et al, 2019 ; Holland, Sun, Gackle, Goldring, & Osmar, 2019 ; Ukweh, Ugbem, Okeke, & Ekpo, 2019 ). In “recognition errors,” abnormalities are foveated too briefly for the observer to correctly recognize them ( Holland et al, 2019 ).…”