Early pregnancy assessment with transvaginal ultrasound scanning

Department of Obstetrics and Gynaecology, McMaster University, Hamilton, Ont.
Canadian Medical Association Journal (Impact Factor: 5.96). 03/1991; 144(4):441-6. DOI: 10.1097/00006254-199110000-00004
Source: PubMed


To establish normal parameters in early pregnancy through transvaginal ultrasonography so that gestational age can be determined and to correlate the sonographic findings with serum human chorionic gonadotropin (hCG) levels calibrated against the first international reference preparation standard.
Infertility clinic.
Thirty-five women with normal intrauterine pregnancy.
Serial measurement of the serum hCG level and the diameter of the gestational sac through transvaginal ultrasonography.
The gestational sac could not be visualized when the hCG level was less than 1100 IU/L. The average growth rate of the sac was 0.9 mm/d. The threshold values for sac diameter, serum hCG level and gestational age below which the yolk sac was not visible were 3.7 mm, 1900 IU/L and 36 days respectively; the corresponding values above which the yolk sac was always visible were 6.7 mm, 5800 IU/L and 40 days. The threshold values below which cardiac activity was not visible were 8.3 mm, 9200 IU/L and 41 days respectively, and the corresponding values above which cardiac activity was always visible were 14.0 mm, 24,000 IU/L and 46 days. The mean gestational ages and the 95% confidence and prediction intervals were tabulated so that measurement of the gestational sac diameter could be used to estimate gestational age early in normal pregnancy.
Transvaginal ultrasonography enables detection of an intrauterine sac and reliable estimation of gestational age on the basis of sac dimensions before an embryo can be seen.

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Available from: Ray Lappalainen, Jan 06, 2016
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    • "Several anatomical parameters are useful in the assessment of gestational age. In early pregnancy, we use mean sac diameter(MSD) (Fossum et al (1988), Bree et al (1989), Daya et al (1991), and crown rump length (CRL)4 to assess gestational age. In second and third trimesters, we use four main anatomic parameters viabiparietal diameter5, head circumference, abdominal circumference Hadlock et al (1982), and femur length. "
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    ABSTRACT: Correct assessment of gestational age is a cornerstone of management of any obstetric case. Several anatomical parameters are useful in the assessment of gestational age. The ultimate aim of this study is to determine the fetal gestational age through the measurement of the foot(foot length) and to determine the accuracy of fetal foot length in estimating gestational age. Methods: There were one hundred pregnant ladies in 2nd and 3rd trimesters had been selected randomly in different medical centers and hospitals in Khartoum State. They were scanned with ultrasound using the international protocols and guidelines of obstetric ultrasonography. Statistical analysis using regression equation and correlation was obtained. Results: There was a strong correlation between fetal foot length and gestaional age. Conclusion: Fetal foot length is a reliable parameter for use in the assessment of gestational age and is particularly useful when other parameters do not accurately predict gestational age. The study derived an important equation to estimate the GA, the GA= 82.411+2.191FtL. [Moawia Gameraddin, Suliman Salih, Mohamed yousef. Evaluation of Gestational Age with Fetal Foot Length Using Ultrasonography. J Am Sci 2014;10(1):5-7]. (ISSN:
    Full-text · Article · Jan 2014
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    ABSTRACT: Pregnancy can be detected early using transvaginal ultrasonography and human chorionic gonadotropin (hCG) measurements. The purpose of this study was to correlate serum hCG levels with transvaginal gestational sac measurements. The mean sac diameter (MSD) and gestational sac diameter (GSD) were calculated as the mean and cube root of the product, respectively, of three sac dimensions taken at right angles. A nonlinear relationship between hCG (natural logarithm) and MSD and GSD was observed. The data were best fitted by a second order polynomial regression model (r2 = 0.98), thereby establishing normal hCG levels for various gestational sac dimensions in early pregnancy.
    No preview · Article · Mar 1991 · Journal of Clinical Ultrasound

  • No preview · Article · Nov 1991 · Obstetrics and Gynecology
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