The effect of biacromial and bideltoid distance on shoulder dystocia and birth weight in newborns

Objective: To evaluate the relationship between neonatal biacromial and bideltoid diameter (BDD), birth weight and shoulder dystocia (SD). Material and Methods: This was a prospective observational study conducted on 161 pregnancies who applied to Private Lokman Hekim Hospital for follow-up between February 2021 and August 2021. Maternal height, weight, parity, and presence of SD in the second stage of labor were evaluated in the patients included in the study. The weight, height, head circumference, biacromial and BDD measurements of newborn babies were taken within the first two hours after birth. The primary purpose of the study was to evaluate the relationship between the biacromial and BDD and SD. The secondary purpose of the study was to evaluate the relationship between the biacromial and BDD and macrosomia. Results: The mean age and post-pregnancy body mass index of the participants were 31.3±4.4 years and 29.0±4.0 kg/m2, respectively, and 42.9% (n=69) delivered vaginally. The incidence of macrosomia was 6.8% (n=11) in all women and the incidence of SD was 7.2% (n=5) in women who had vaginal deliveries. The mean biacromial diameter (BAD) was 12.4±1.0 cm and the mean BDD was 18.2±1.7 cm. A correlation rate of 0.373 was found between SD and the BAD, and 0.484 between SD and the BDD. The correlation coefficients between macrosomia and the biacromial and BDD were 0.213 and 0.420, respectively. In cases in which the BDD was ≥21 cm, the sensitivity for SD was 100%, the specificity was 90.63%, and the accuracy was 91.30%. The cut-off point for the BAD was ≥14 cm, and the sensitivity and specificity for SD was 63.64% and 89.33%, respectively. The highest correlation for SD was obtained in cases in which there was a history of SD (0.648). Conclusion: The relationship between neonatal biacromial and BDD, and macrosomia and SD were significant. There was no difference between the correlation values of the two measurements in terms of SD. However, the correlation coefficient of the BDD was greater for macrosomia.

A new approach to predicting shoulder dystocia: fetal clavicle measurement

Background/aim: This study aimed to evaluate the relationship between second- and third-trimester clavicle lengths and birth weight and shoulder dystocia. Materials and methods: This prospective observational study included 181 patients who presented to the Private Etlik Lokman Hekim Hospital for routine pregnancy visits between March 2019 and March 2020. In addition to routine pregnancy examinations, the patients also underwent ultrasonography twice at weeks 20­23 and 33­36 to determine the length of the fetal clavicle. The patients were evaluated for shoulder dystocia in the second stage of labor. The birth weight of the neonates was recorded. The primary objective of this study was to establish the relationship between third-trimester clavicle length and shoulder dystocia. Results: Fetal clavicle length increases in the second trimester with the advancing gestational week but does not significantly change in the third trimester. We did not observe any significant difference for second trimester clavicle length between the type of delivery, birth weight, or shoulder dystocia. Moreover, we did not observe any significant difference for third trimester clavicle length between types of delivery. However, we found a significant relationship between third trimester clavicle length and birth weight and shoulder dystocia. The median third-trimester clavicle length was 39.5 mm (range: 30.7­43.9) in neonates who did not develop shoulder dystocia and 42.5 mm (range: 41.4­43.1) in the 3 neonates who developed shoulder dystocia. The third-trimester clavicle length cut-off for shoulder dystocia was calculated as 41.35 mm (sensitivity: 100.00%, specificity: 83.82%, accuracy: 84.5%). The third-trimester clavicle length cut-off for macrosomia (defined as birth weight of ≥4100 g) was 40.75 mm (sensitivity: 87.50%, specificity: 77.56%, accuracy: 78.05%). Conclusion: Third-trimester fetal clavicle length, an important component of biacromial diameter, as measured by ultrasonography, is a practical and significant method for predicting macrosomia and shoulder dystocia.