Prediction of large‐for‐gestational‐age neonate by routine third‐trimester ultrasound

Khan, Naila Zaman; Ciobanu, Anca Marina; Karampitsakos, Theodoros; Akolekar, Ranjit; Nicolaides, Kypros H.

doi:10.1002/uog.20377

Cited by 48 publications

(41 citation statements)

References 27 publications

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“…There is now good evidence that, first, about 85% of SGA neonates are born at term 6 , second, the best way to identify such SGA and LGA fetuses is by routine sonography at 35 + 0 to 36 + 6 weeks' gestation [6][7][8][9]15 , and, third, the most accurate model for assessment of EFW is that reported by Hadlock et al, which combines ultrasonographic measurements of fetal AC, HC and FL 16,17 . However, as demonstrated in this study, measurement error in fetal biometry can cause substantial error in EFW, resulting in misclassification of both SGA and LGA neonates.…”

Section: Discussionmentioning

confidence: 99%

“…As demonstrated in this study, it would be necessary to improve this process further to reduce errors in measurements and this could potentially be achieved by sonographers repeating measurements when EFW is near the cut-off of interest, such as the 10 th or 90 th percentile. The third approach for potential improvement of the performance of prenatal prediction of adverse perinatal outcome in pregnancies undergoing routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation is to accept the limitations of sonographic EFW at the cut-offs of the 10 th and 90 th percentiles, respectively, and base clinical management, including serial scans, on an EFW cut-off of the 40 th percentile together with findings of fetal Doppler indices for SGA fetuses 18 and the 70 th percentile for LGA fetuses 15 .…”

Section: Discussionmentioning

confidence: 99%

“…However, data from implementation of a routine scan in 45 847 singleton pregnancies at 35 + 0 to 36 + 6 weeks' gestation showed that screening by sonographic EFW < 10 th percentile predicted only 70% of neonates with birth weight < 10 th percentile born within 2 weeks after assessment and about 45% of those born at any stage after assessment 18 . Similarly, EFW > 90 th percentile predicted only 71% of neonates with birth weight > 90 th percentile born within 10 days after the scan and 46% of those born at ≥ 37 weeks' gestation 15 . Possible explanations for the performance of EFW being only modest include, first, that some fetuses with EFW > 10 th percentile at the time of the scan may become SGA in the subsequent weeks before birth and some of those with EFW < 90 th percentile at the time of the scan may become LGA in the subsequent weeks before birth, and, second, that the measurements of AC, HC and FL used in the formula for EFW are imprecise.…”

Section: Introductionmentioning

confidence: 94%

“…Such risks could potentially be reduced by elective Cesarean section or early induction of labor to reduce the inevitable increase in fetal size with advancing gestational age [12][13][14] . As in cases of a SGA neonate, the best prediction of a LGA neonate is achieved by universal sonographic fetal biometry at 35 + 0 to 36 + 6 weeks' gestation 7,15 .…”

Section: Introductionmentioning

confidence: 99%

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Impact of biometric measurement error on identification of small‐ and large‐for‐gestational‐age fetuses

Wright

Smith³

et al. 2020

Ultrasound in Obstet & Gyne

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CONTRIBUTION What are the novel findings of this work?This study examines the impact of measurement errors in fetal head circumference, abdominal circumference and femur length on sonographic estimated fetal weight (EFW) and their effect on the prediction of small-(SGA) and large-(LGA) for-gestational-age fetuses.What are the clinical implications of this work? Measurement error in fetal biometry causes substantial error in EFW, resulting in misclassification of SGA and LGA fetuses. The extent to which improvement can be achieved through effective quality assurance remains to be seen but, as a first step, it is important for practitioners to understand how biometric measurement error impacts on the prediction of SGA and LGA fetuses. ABSTRACTObjectives First, to obtain measurement-error models for biometric measurements of fetal abdominal circumference (AC), head circumference (HC) and femur length (FL), and, second, to examine the impact of biometric measurement error on sonographic estimated fetal weight (EFW) and its effect on the prediction of small-(SGA) and large-(LGA) for-gestational-age fetuses with EFW < 10 th and > 90 th percentile, respectively.Methods Measurement error standard deviations for fetal AC, HC and FL were obtained from a previous large study on fetal biometry utilizing a standardized measurement protocol and both qualitative and quantitative quality-control monitoring. Typical combinations of AC, HC and FL that gave EFW on the 10 th and 90 th percentiles were determined. A Monte-Carlo simulation study was carried out to examine the effect of measurement error on the classification of fetuses as having EFW above or below the 10 th and 90 th percentiles. ResultsErrors were assumed to follow a Gaussian distribution with a mean of 0 mm and SDs, obtained from a previous well-conducted study, of 6.93 mm for AC, 5.15 mm for HC and 1.38 mm for FL. Assuming errors according to such distributions, when the 10 th and 90 th percentiles are used to screen for SGA and LGA fetuses, respectively, the detection rates would be 78.0% at false-positive rates of 4.7%. If the cut-offs were relaxed to the 30 th and 70 th percentiles, the detection rates would increase to 98.2%, but at false-positive rates of 24.2%. Assuming half of the spread in the error distribution, using the 10 th and 90 th percentiles to screen for SGA and LGA fetuses, respectively, the detection rates would be 86.6% at false-positive rates of 2.3%. If the cut-offs were relaxed to the 15 th and 85 th percentiles, respectively, the detection rates would increase to 97.0% and the false-positive rates would increase to 6.3%.Conclusions Measurement error in fetal biometry causes substantial error in EFW, resulting in misclassification of SGA and LGA fetuses. The extent to which improvement can be achieved through effective quality assurance remains to be seen but, as a first step, it is important for practitioners to understand how biometric measurement error impacts the prediction of SGA and LGA fetuses.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of biometric measurement error on identification of small‐ and large‐for‐gestational‐age fetuses

Wright

Smith³

et al. 2020

Ultrasound in Obstet & Gyne

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“…Routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation is beneficial for the diagnosis of previously undetected fetal abnormalities, prediction of pre‐eclampsia, prediction of small‐ and large‐for‐gestational‐age neonates and assessment of fetal oxygenation. Another potential benefit of a routine scan at 35 + 0 to 36 + 6 weeks' gestation is the diagnosis of non‐cephalic presentation.…”

Section: Introductionmentioning

confidence: 99%

Value of routine ultrasound examination at 35–37 weeks' gestation in diagnosis of non‐cephalic presentation

Castro

Ciobanu

Formuso

et al. 2020

Ultrasound in Obstet & Gyne

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CONTRIBUTIONWhat are the novel findings of this work? This study reports the incidence of non-cephalic presentation at a routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation and subsequent management of such pregnancies. What are the clinical implications of this work?Routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation detects non-cephalic presentation in about 5% of pregnancies. Such diagnosis could potentially improve pregnancy outcome by preventing unexpected abnormal presentation in labor and, through external cephalic version, reducing the incidence of non-cephalic presentation. ABSTRACTObjective Undiagnosed non-cephalic presentation in labor carries increased risks for both the mother and baby. Routine pregnancy care based on maternal abdominal palpation fails to detect the majority of cases of non-cephalic presentation. The aim of this study was to report the incidence of non-cephalic presentation at a routine scan at 35 + 0 to 36 + 6 weeks' gestation and the subsequent management of such pregnancies. MethodsThis was a retrospective analysis of prospectively collected data in 45 847 singleton pregnancies that had undergone routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation. Patients with breech or transverse/oblique presentation were divided into two groups; first, those who would have elective Cesarean section for fetal or maternal indications other than the abnormal presentation, and, second, those who would potentially require external cephalic version (ECV). The latter group was reassessed after 1-2 weeks and, if there was persistence of abnormal presentation, the parents were offered the option of ECV or elective Cesarean section at 38-40 weeks' gestation. Multivariable logistic regression analysis was carried out to determine which of the factors from maternal and pregnancy characteristics provided a significant contribution in the prediction of, first, non-cephalic presentation at the 35 + 0 to 36 + 6-week scan, second, successful ECV from non-cephalic to cephalic presentation, and, third, spontaneous rotation from non-cephalic to cephalic presentation that persisted until delivery.Results First, at 35 + 0 to 36+ 6 weeks, the fetal presentation was cephalic in 43 416 (94.7%) pregnancies, breech in 1987 (4.3%) and transverse or oblique in 444 (1.0%). Second, multivariable analysis demonstrated that the risk of non-cephalic presentation increased with increasing maternal age and weight, decreasing height and earlier gestational age at scan, was higher in the presence of placenta previa, oligohydramnios or polyhydramnios and in nulliparous than parous women, and was lower in women of South Asian or mixed racial origin than in white women. Third, 22% of cases of non-cephalic presentation were not eligible for ECV because of planned Cesarean section for indications other than the malpresentation. Fourth, of those eligible for ECV, only 48.5% (646/1332) agreed to the procedure, which was successful in 39.0% (252/646) of cases. Fifth, the chance of successful...

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Obstetric consequences of a false‐positive diagnosis of large‐for‐gestational‐age fetus

Papaccio

Fichera

Nava

et al. 2021

Intl J Gynecology & Obste

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The American College of Obstetricians and Gynecologists (ACOG), describes large for gestational age (LGA) as a birth weight equal to or greater than the 90th centile for a given gestational age, while macrosomia, whose definition is more controversial, is described as a birth weight over 4000 or 4500 g, unrelated to gestational age. 1 A variety of maternal factors predispose to high infant birth weight: pre-existing diabetes or gestational diabetes, pre-pregnancy obesity, gestational weight gain, high birth weight in previous pregnancies, multiparity and ethnicity. 1 LGA fetuses are associated with

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Prediction of large‐for‐gestational‐age neonate by routine third‐trimester ultrasound

Cited by 48 publications

References 27 publications

Impact of biometric measurement error on identification of small‐ and large‐for‐gestational‐age fetuses

Impact of biometric measurement error on identification of small‐ and large‐for‐gestational‐age fetuses

Value of routine ultrasound examination at 35–37 weeks' gestation in diagnosis of non‐cephalic presentation

Obstetric consequences of a false‐positive diagnosis of large‐for‐gestational‐age fetus

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