Israel Medical Association Journal

Background: The sonographic assessment of estimated fetal weight (EFW) is essential for identification of fetuses in weight extremes and aids in peripartum management. However, there are inconsistent reports regarding EFW accuracy.

Objective: To examine maternal and fetal determinants associated with unreliable EFW.

Methods: A retrospective case-control study was conducted at a single, tertiary medical center between 2011 and 2019. All term, singleton deliveries with a sonographic EFW within 2 weeks of delivery were included. Unreliable EFW was defined as > 500 grams discordance between it and the actual birth weight. We allocated the study cohort into two groups: unreliable EFW (cases) and accurate EFW (controls).

Results: Overall, 41,261 deliveries met inclusion criteria. Of these, 1721 (4.17%) had unreliable EFW. The factors positively associated with unreliable EFW included body mass index > 30 kg/m², weight gain > 20 kg, higher amniotic fluid index, pregestational diabetes, gestational age > 41^0/7, and birth weight ≥ 4000 grams. On multiple regression analysis, pregestational diabetes (odds ratio [OR] 2.22, 95% confidence interval [95%CI] 1.56–3.17, P < 0.001) and a higher birth weight (OR 1.91, 95%CI 1.79–2.04, P < 0.001) were independently associated with unreliable EFW. On analysis of different weight categories, pregestational diabetes was associated with unreliable EFW only among birth weights ≥ 3500 grams (OR 3.28, 95%CI 1.98–5.44, P< 0.001) and ≥ 4000 grams (OR 4.27, 95%CI 2.31–7.90, P < 0.001).

Conclusion: Pregestational diabetes and increased birth weight are independent risk factors for unreliable EFW and should be considered when planning delivery management.

Background: Sonographic estimation of birth weight may differ among evaluators due to its operator-dependent nature.

Objectives: To compare the accuracy of estimation of fetal birth weight by sonography between ultrasound-certified physicians and registered diagnostic medical technicians.

Methods: The authors reviewed ultrasound examinations that had been performed by either technicians or ultrasound-certified obstetricians between 2010 and 2017, and within 2 days of delivery. Inclusion criteria were: singleton viable pregnancy, details of four ultrasound measurements (abdominal circumference, bi-parietal diameter, head circumference, and femur length), and known birth weight. The estimated fetal weight (EFW) was calculated according to the Hadlock formula, incorporating the four ultrasound measurements. The mean percentage error (MPE) was calculated by the formula: (EFW-birth weight) x100 / birth weight.

Results: Technicians performed 9741examinations and physicians performed 352 examinations. The proportion of macrosomic neonates was similar in both groups. Technicians were more accurate than physicians in terms of the MPE, absolute MPE, proportion of estimates that fell within ± 10% of birth weight, and Euclidean distance (P < 0.0001 for all comparisons). They were also more accurate in terms of sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating curve. Furthermore, for fetuses weighing more than 4000 grams the technicians had a lower total false prediction rate.

Conclusions: Medical technicians in our institute performed better than physicians in estimating fetal weight. Further studies are warranted to confirm our findings and better delineate the role of repeat physician’s examination after an initial estimation by an experienced technician.

Background: Risk factors for bleeding complications after percutaneous kidney biopsy (PKB) and the role of primary hemostasis screening are not well established.

Objectives: To determine the role of primary hemostasis screening and complication outcomes among individuals who underwent PKB.

Methods: We reviewed data of 456 patients who underwent PKB from 2010 to 2016 in a large university hospital. In 2015, bleeding time (BT) testing was replaced by light transmission aggregometry (LTA) as a pre-PKB screening test.

Results: Of the 370 patients who underwent pre-PKB hemostasis screening by BT testing, prolonged BT was observed in 42 (11.3%). Of the 86 who underwent LTA, an abnormal response was observed in 14 (16.3%). Overall, 155 (34.0%) patients experienced bleeding: 145 (31.8%) had minor events (hemoglobin fall of 1–2 g/dl, macroscopic hematuria, perinephric hematoma without the need for transfusion or intervention) and 17 (3.7%) had major events (hemoglobin fall > 2 g/dl, blood transfusion or further intervention). Abnormal LTA response did not correlate with bleeding (P = 0.80). In multivariate analysis, only prolonged BT (P = 0.0001) and larger needle size (P = 0.005) were identified as independent predictors of bleeding.

Conclusions: Bleeding complications following PKB were common and mostly minor, and the risk of major bleeding was low. Larger needle size and prolonged BT were associated with a higher bleeding risk. Due to the relatively low risk of major bleeding and lack of benefit of prophylactic intervention, the use of pre-PKB hemostasis screening remains unestablished.