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Longitudinal reference ranges for fetal ultrasound biometry in twin pregnancies.

Liao AW, Brizot Mde L, Kang HJ, Assunção RA, Zugaib M - Clinics (Sao Paulo) (2012)

Bottom Line: Women who abandoned follow-up, pregnancies with unknown outcomes or pregnancies with complications were excluded.A total of 807 ultrasound examinations were performed in 125 twin pregnancies between 14 and 38 weeks of gestation (6.5 ± 1.4 scans/pregnancy).Values corresponding to the 10(th), 50(th), and 90(th) percentiles for estimated fetal weight at 28, 32, and 36 weeks, respectively, were as follows: 937, 1,096, 1,284 g; 1,462, 1,720, 2,025 g; and 2,020, 2,399, 2,849 g.

View Article: PubMed Central - PubMed

Affiliation: Hospital das Clínicas, Instituto Central, Faculdade de Medicina, Universidade de São Paulo, Department of Obstetrics and Gynecology, Brazil. liao@usp.br

ABSTRACT

Objective: The purpose of this study was to establish longitudinal reference ranges for fetal ultrasound biometry measurements and growth parameters in twin pregnancies.

Method: A total of 200 uncomplicated twin pregnancies before 21 weeks of gestation were recruited for this prospective, longitudinal study. Women who abandoned follow-up, pregnancies with unknown outcomes or pregnancies with complications were excluded. Ultrasound scans were performed every three weeks, and biparietal and occipitofrontal diameters, head and abdominal circumferences, and femur diaphysis length measurements were obtained for each fetus at each visit. Estimated fetal weight, biparietal/occipitofrontal diameter, head circumference/abdominal circumference, and femur diaphysis length/abdominal circumference ratios were also calculated. Multilevel regression analysis was performed on normalized data.

Results: A total of 807 ultrasound examinations were performed in 125 twin pregnancies between 14 and 38 weeks of gestation (6.5 ± 1.4 scans/pregnancy). Regression analysis demonstrated significant correlations for all variables with gestational age, namely log of the biparietal diameter (r = 0.98), log of the occipitofrontal diameter (r = 0.98), log of the head circumference (r = 0.99), log of the abdominal circumference (r = 0.98), square root of the femur length (r = 0.99), log of the estimated fetal weight (r = 0.99), biparietal/occipitofrontal ratio (r = -0.11), head/abdomen circumference ratio (r = -0.56), and log of the femur length/abdominal circumference ratio (r = 0.61). Values corresponding to the 10(th), 50(th), and 90(th) percentiles for estimated fetal weight at 28, 32, and 36 weeks, respectively, were as follows: 937, 1,096, 1,284 g; 1,462, 1,720, 2,025 g; and 2,020, 2,399, 2,849 g.

Conclusion: In twin pregnancies, fetal ultrasound biometry measurements and growth parameters show a significant correlation with gestational age.

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Related in: MedlinePlus

Ultrasound images demonstrating the transverse section of the fetal head (A), abdomen (B) and femur length (C). Markers are placed depicting measurements of the biparietal (BPD), occipitofrontal (OFD), antero-posterior (APAD) and transverse abdominal (TAD) diameters and femur diaphysis length (FL).
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f1-cln_67p451: Ultrasound images demonstrating the transverse section of the fetal head (A), abdomen (B) and femur length (C). Markers are placed depicting measurements of the biparietal (BPD), occipitofrontal (OFD), antero-posterior (APAD) and transverse abdominal (TAD) diameters and femur diaphysis length (FL).

Mentions: At each visit, BPD, occipitofrontal diameter (OFD), HC, AC, and FL measurements were obtained for each fetus according to standard techniques (Figure 1) (6). Fetal weight was estimated according to the mathematical formula proposed by Hadlock et al. (7), and BPD/OFD, HC/AC, and FL/AC ratios were calculated for each fetus.


Longitudinal reference ranges for fetal ultrasound biometry in twin pregnancies.

Liao AW, Brizot Mde L, Kang HJ, Assunção RA, Zugaib M - Clinics (Sao Paulo) (2012)

Ultrasound images demonstrating the transverse section of the fetal head (A), abdomen (B) and femur length (C). Markers are placed depicting measurements of the biparietal (BPD), occipitofrontal (OFD), antero-posterior (APAD) and transverse abdominal (TAD) diameters and femur diaphysis length (FL).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3351246&req=5

f1-cln_67p451: Ultrasound images demonstrating the transverse section of the fetal head (A), abdomen (B) and femur length (C). Markers are placed depicting measurements of the biparietal (BPD), occipitofrontal (OFD), antero-posterior (APAD) and transverse abdominal (TAD) diameters and femur diaphysis length (FL).
Mentions: At each visit, BPD, occipitofrontal diameter (OFD), HC, AC, and FL measurements were obtained for each fetus according to standard techniques (Figure 1) (6). Fetal weight was estimated according to the mathematical formula proposed by Hadlock et al. (7), and BPD/OFD, HC/AC, and FL/AC ratios were calculated for each fetus.

Bottom Line: Women who abandoned follow-up, pregnancies with unknown outcomes or pregnancies with complications were excluded.A total of 807 ultrasound examinations were performed in 125 twin pregnancies between 14 and 38 weeks of gestation (6.5 ± 1.4 scans/pregnancy).Values corresponding to the 10(th), 50(th), and 90(th) percentiles for estimated fetal weight at 28, 32, and 36 weeks, respectively, were as follows: 937, 1,096, 1,284 g; 1,462, 1,720, 2,025 g; and 2,020, 2,399, 2,849 g.

View Article: PubMed Central - PubMed

Affiliation: Hospital das Clínicas, Instituto Central, Faculdade de Medicina, Universidade de São Paulo, Department of Obstetrics and Gynecology, Brazil. liao@usp.br

ABSTRACT

Objective: The purpose of this study was to establish longitudinal reference ranges for fetal ultrasound biometry measurements and growth parameters in twin pregnancies.

Method: A total of 200 uncomplicated twin pregnancies before 21 weeks of gestation were recruited for this prospective, longitudinal study. Women who abandoned follow-up, pregnancies with unknown outcomes or pregnancies with complications were excluded. Ultrasound scans were performed every three weeks, and biparietal and occipitofrontal diameters, head and abdominal circumferences, and femur diaphysis length measurements were obtained for each fetus at each visit. Estimated fetal weight, biparietal/occipitofrontal diameter, head circumference/abdominal circumference, and femur diaphysis length/abdominal circumference ratios were also calculated. Multilevel regression analysis was performed on normalized data.

Results: A total of 807 ultrasound examinations were performed in 125 twin pregnancies between 14 and 38 weeks of gestation (6.5 ± 1.4 scans/pregnancy). Regression analysis demonstrated significant correlations for all variables with gestational age, namely log of the biparietal diameter (r = 0.98), log of the occipitofrontal diameter (r = 0.98), log of the head circumference (r = 0.99), log of the abdominal circumference (r = 0.98), square root of the femur length (r = 0.99), log of the estimated fetal weight (r = 0.99), biparietal/occipitofrontal ratio (r = -0.11), head/abdomen circumference ratio (r = -0.56), and log of the femur length/abdominal circumference ratio (r = 0.61). Values corresponding to the 10(th), 50(th), and 90(th) percentiles for estimated fetal weight at 28, 32, and 36 weeks, respectively, were as follows: 937, 1,096, 1,284 g; 1,462, 1,720, 2,025 g; and 2,020, 2,399, 2,849 g.

Conclusion: In twin pregnancies, fetal ultrasound biometry measurements and growth parameters show a significant correlation with gestational age.

Show MeSH
Related in: MedlinePlus