<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_JoU.2022.0007_s_006"><h3>Aim</h3><p>To compare the accuracy of biparietal diameter and transcerebellar diameter in measuring the gestational age during the third trimester of pregnancy.</p></sec><sec id="j_JoU.2022.0007_s_007"><h3>Material and methods</h3><p>In this prospective observational study, 275 pregnant women with singleton pregnancy between 32 and 37 weeks gestational age were recruited from the outpatient clinics of both Helwan University Hospital and Ain Shams University Maternity Hospital, Cairo, Egypt, during the period from February 2021 to August 2021. Transcerebellar and biparietal diameters of the fetus were measured by a radiologist blinded to the women’s gestational age, and compared to the gestational age acquired from a reliable date of first day of last menstrual period.</p></sec><sec id="j_JoU.2022.0007_s_008"><h3>Results</h3><p>The gestational age calculated by first day of last menstrual period ranged from 32 to 37 weeks (34.35 ± 1.4), while estimated by transcerebellar and biparietal diameters ranged from 31 to 37 weeks (34.31 ± 1.39) and 31 to 39 weeks (34.32 ± 1.44), respectively. There was a strong positive correlation between gestational age and transcerebellar diameter (<italic>r</italic> = 0.98, <italic>p</italic> &lt;0.001) as well as biparietal diameter (<italic>r</italic> = 0.87, <italic>p</italic> &lt;0.001), yet a stronger correlation was with transcerebellar diameter. 93.6% of gestational age assessment by transcerebellar diameter was correct compared to only 79.9% by biparietal diameter.</p></sec><sec id="j_JoU.2022.0007_s_009"><h3>Conclusions</h3><p>Transcerebellar diameter is a reliable single sonographic fetal biometric parameter for the assessment of gestational age in third trimester of pregnancy.</p></sec></abstract>

AimTo compare the accuracy of biparietal diameter and transcerebellar diameter in measuring the gestational age during the third trimester of pregnancy.Material and methodsIn this prospective observational study, 275 pregnant women with singleton pregnancy between 32 and 37 weeks gestational age were recruited from the outpatient clinics of both Helwan University Hospital and Ain Shams University Maternity Hospital, Cairo, Egypt, during the period from February 2021 to August 2021. Transcerebellar and biparietal diameters of the fetus were measured by a radiologist blinded to the women’s gestational age, and compared to the gestational age acquired from a reliable date of first day of last menstrual period.ResultsThe gestational age calculated by first day of last menstrual period ranged from 32 to 37 weeks (34.35 ± 1.4), while estimated by transcerebellar and biparietal diameters ranged from 31 to 37 weeks (34.31 ± 1.39) and 31 to 39 weeks (34.32 ± 1.44), respectively. There was a strong positive correlation between gestational age and transcerebellar diameter (r = 0.98, p <0.001) as well as biparietal diameter (r = 0.87, p <0.001), yet a stronger correlation was with transcerebellar diameter. 93.6% of gestational age assessment by transcerebellar diameter was correct compared to only 79.9% by biparietal diameter.ConclusionsTranscerebellar diameter is a reliable single sonographic fetal biometric parameter for the assessment of gestational age in third trimester of pregnancy.

Transcerebellar diameter versus biparietal diameter for the measurement of gestational age in third trimester

Journal of Ultrasonography

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AimTo compare the accuracy of biparietal diameter and transcerebellar diameter in measuring the gestational age during the third trimester of...

	Intra-class correlation (ICC)	95% confidence interval		F test with true value 0
	Intra-class correlation (ICC)	Lower bound	Upper bound	Value	Sig
Single measures	0.978	0.973	0.983	91.849	<0.001 HS
Average measures	0.989	0.986	0.991	91.849	<0.001 HS

		Min.	Max.	Mean	SD
Age (years)		18.00	34.00	24.00	3.85
BMI (kg/m²)		21.00	34.00	27.51	3.63
AFI (cm)		9.00	17.00	12.34	2.16
		N		%
Parity	1	124		41.5%
	2	97		32.4%
	3	56		18.7%
	4	22		7.4%
	Total	299		100.0%

		N	%	P value*
Correct assessment of GA by TCD	Yes	280	93.6%	<0.001 HS
Correct assessment of GA by TCD	No	19	6.4%
Correct assessment of GA by BPD	Yes	239	79.9%
Correct assessment of GA by BPD	No	60	20.1%

	Intra-class correlation (ICC)	95% confidence interval		F test with true value 0
	Intra-class correlation (ICC)	Lower bound	Upper bound	Value	Sig
Single measures	0.870	0.839	0.895	14.378	<0.001 HS
Average measures	0.930	0.913	0.945	14.378	<0.001 HS

Study	Pearson correlation	P-value
This study	0.98	<0.001
Chavez et al.⁽¹⁵⁾	0.95	0.001
Reddy et al.⁽¹²⁾	0.982	0.0004
George et al.⁽¹⁴⁾	0.995	<0.001
Bavini et al.⁽¹¹⁾	0.971	<0.0001

Transcerebellar diameter versus biparietal diameter for the measurement of gestational age in third trimester

Article Category: Research paper

Published Online: Feb 08, 2022

Page range: 39 - 43

Received: Aug 20, 2021

Accepted: Oct 20, 2022

DOI: https://doi.org/10.15557/JoU.2022.0007

Keywords
gestational age, third trimester, transcerebellar diameter, biparietal diameter

© 2022 Mohamed Adel Ali, Eman AbdElSalam NasrElDin, Mahmoud Moussa, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Intra-class correlation coefficient for agreement between GA measured by TCD and GA measured by LMP

Demographic characteristics of study participants

Comparison between TCD and BPD regarding correct assessment of GA (accuracy of GA assessment)

Intra-class correlation coefficient for agreement between GA measured by BPD and GA measured by LMP

Accuracy of TCD for GA estimation in the 3rd trimester compared to the results of other studies

Transcerebellar diameter versus biparietal diameter for the measurement of gestational age in third trimester

Article Category: Research paper

Published Online: Feb 08, 2022

Page range: 39 - 43

Received: Aug 20, 2021

Accepted: Oct 20, 2022

DOI: https://doi.org/10.15557/JoU.2022.0007

Keywordsgestational age, third trimester, transcerebellar diameter, biparietal diameter

© 2022 Mohamed Adel Ali, Eman AbdElSalam NasrElDin, Mahmoud Moussa, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Intra-class correlation coefficient for agreement between GA measured by TCD and GA measured by LMP

Demographic characteristics of study participants

Comparison between TCD and BPD regarding correct assessment of GA (accuracy of GA assessment)

Intra-class correlation coefficient for agreement between GA measured by BPD and GA measured by LMP

Accuracy of TCD for GA estimation in the 3rd trimester compared to the results of other studies

Keywords
gestational age, third trimester, transcerebellar diameter, biparietal diameter