Evaluation of Placental Volume at 7–10 + 6 Weeks of Pregnancy by 3D-Sonography

• Published in: Placenta (Eastbourne) Vol. 30; no. 7; pp. 585 - 589
• Main Authors: Nardozza, L.M.M, Nowak, P.M, Araujo, E, Guimarães Filho, H.A, Rolo, L.C, Torloni, M.R, Moron, A.F
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2009; Elsevier
• Subjects: Adult; Biological and medical sciences; Cross-Sectional Studies; Crown–rump length; Early placental phase; Embryology: invertebrates and vertebrates. Teratology; Female; First trimester of pregnancy; Fundamental and applied biological sciences. Psychology; Humans; Imaging, Three-Dimensional; Internal Medicine; Observer Variation; Obstetrics and Gynecology; Organ volume; Placenta - diagnostic imaging; Pregnancy; Pregnancy Trimester, First; Reference Values; Reproducibility of Results; Three-dimensional imaging; Ultrasonography, Prenatal - methods; Ultrasonography, Prenatal - standards; Ultrasonography, Prenatal - statistics & numerical data; Young Adult; First trimester of pregnancy; Crown–rump length; Organ volume; Three-dimensional imaging; Early placental phase; Sonography; Pregnancy; Vertebrata; Mammalia; Placenta; Fetal membrane; Volume
• ISSN: 0143-4004; 1532-3102
• DOI: 10.1016/j.placenta.2009.04.008

Abstract The aim of the study was to establish normative data for placental volume (PV) at 7–10 + 6 weeks of gestation using three-dimensional ultrasound (3DUS). The cross-sectional study involved 70 healthy pregnancies between 7 and 11 weeks. The VOCAL (Virtual Organ Computer-aided Analysis) method with a 30° rotation angle and six planes was used for volumetric calculations. Regression models were constructed to assess the correlation between PV and crown–rump length (CRL) adjusted by the determination coefficient ( R2 ). The method proposed by Royston and Wright was used to establish the 2.5th; 10th; 50th; 90th and 97.5th percentiles (percentile = mean + K × SD). The intraclass correlation coefficient (ICC), Bland–Altman graphs and Student’s paired t -tests were used to assess intra- and interobserver variability. PV ranged from 1.7 to 42.6 cm3 , with a mean of 13.6 cm3 (±9.4 cm3 ). There was a strong correlation between PV and CRL; the exponential equation was the model that best expressed the correlation between them ( R2 = 0.76). For CRL between 9 and 40 mm, the mean PV increased 10.5 times, while CRL increased only 4.4 times. Inter- and intraobserver correlation were excellent (ICC = 0.979 and 0.971, respectively). Bland–Altman graphs indicated a good reproducibility with a mean intraobserver and interobserver difference of 0.2 cm3 (95% CI: −0.7–1.2 cm3 ) and −0.2 cm3 (95% CI: −1.3–0.9 cm3 ), respectively. Reference limits were generated for first trimester PV assessed by 3DUS using the VOCAL method. There is a strong correlation between PV and CRL. Placental volume obtained through this method was highly reproducible.