Accuracy of supervised measurement of fetal weight in a residency program

• Published in: Journal of clinical ultrasound Vol. 53; no. 1; pp. 84 - 89
• Main Authors: Brambila‐Rodríguez, Ana Fabianne, Villalobos, Guillermo De La Cruz, Domínguez‐Rodríguez, Juan Joel, Oviedo‐Cruz, Héctor
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.01.2025; Wiley Subscription Services, Inc
• Subjects: Abnormalities; Accuracy; Adult; Bias; Birth weight; Clinical Competence - statistics & numerical data; Cross-Sectional Studies; Female; Fetal Weight; Fetuses; Humans; Internship and Residency; medical education; Medical personnel; obstetrics ultrasound; Parity; Pregnancy; prenatal ultrasonography; Reproducibility of Results; Ultrasonic imaging; Ultrasonography, Prenatal - methods; Ultrasonography, Prenatal - statistics & numerical data; Ultrasound; Weight gain measurement; obstetrics ultrasound; birth weight; prenatal ultrasonography; medical education; fetal weight
• ISSN: 0091-2751; 1097-0096; 1097-0096
• DOI: 10.1002/jcu.23842

Objectives To evaluate the accuracy of ultrasound estimates of fetal weight made by residents. Methods A cross‐sectional study was conducted on consecutive pregnancies attended in an obstetric ward. All participants provided their consent to participate. Inclusion criteria were singleton pregnancies with ultrasound evaluation and delivery within 14 days. Congenital abnormalities and stillbirths were excluded. Ultrasound scans were performed by two residents, one observer per subject, following standardized methodology and supervised by senior staff. Fetal weight was calculated using the four‐parameter Hadlock 1985 formula. Birth weight was measured using a standard clinical scale. Bland–Altman and mixed‐effects analyses were performed. Results In a 6‐month period, 95 gestations were recruited at 30–41 weeks, and birth weights ranged from 1200 to 4080 g. The bias between methods was −28 g (CI95%, −74 to 18) with 95% limits of agreement of ±440 g. The 95% deviation between methods was of ±16%. Parity had the most significant effect on the bias between methods; operator and maternal weight had no significant effect. Conclusions Supervised measurement of fetal weight by residents demonstrated high accuracy. Parity bias may be associated with visceral fat deposition independent of maternal weight gain. A methodology for medical evaluation is presented. Up to 78% of the birth weight can be inferred from supervised prenatal ultrasound. Birth weight resulted ±16% of the estimated fetal weight in 95% of the cases. Parity had the most significant effect on ultrasound measurement bias.