Talk:Ultrasound

• Fetal volume and crown-rump length from 7 to 10 weeks of gestational age in singletons and twins. Martins WP, Nastri CO, Barra DA, Navarro PA, Mauad Filho F, Ferriani RA. Eur J Obstet Gynecol Reprod Biol. 2009 Jul;145(1):32-5. Epub 2009 Apr 21. PMID: 19386409

"Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. CONDENSATION: Fetal volume and crown-rump length were similar between singletons and twins. Fetal volume relative increase was higher and the predicted gestational age was better."

• Fetal crown-rump length and estimation of gestational age in an ethnic Chinese population. Sahota DS, Leung TY, Leung TN, Chan OK, Lau TK. Ultrasound Obstet Gynecol. 2009 Feb;33(2):157-60. PMID: 19115262

"The best-fit equation for the sonographic estimate of gestational age (GA, in days) from CRL (in mm) was GA = 26.643 + 7.822 x CRL(1/2)(R(2) = 0.96). The mean difference between menstrual age and the predicted gestational age was 0.22 days (95% CI, - 0.14 to 0.56), which was lower than that of the three established CRL dating formulae. CONCLUSION: We have derived a formula suitable for the dating of naturally conceived pregnancies between 6 and 15 weeks of gestation that has no systematic prediction error (the 95% CI of mean difference between predicted and menstrual age included zero), comparing favorably with established CRL dating formulae."

• Fetal size in the second trimester is associated with the duration of pregnancy, small fetuses having longer pregnancies. Johnsen SL, Wilsgaard T, Rasmussen S, Hanson MA, Godfrey KM, Kiserud T. BMC Pregnancy Childbirth. 2008 Jul 16;8:25. PMID: 18627638 | BMC

• Functional linear discriminant analysis: a new longitudinal approach to the assessment of embryonic growth. Bottomley C, Daemen A, Mukri F, Papageorghiou AT, Kirk E, Pexsters A, De Moor B, Timmerman D, Bourne T. Hum Reprod. 2009 Feb;24(2):278-83. Epub 2008 Oct 31. PMID: 18978027 | Hum Reprod.

• Fetal age assessment based on 2nd trimester ultrasound in Africa and the effect of ethnicity. Salpou D, Kiserud T, Rasmussen S, Johnsen SL. BMC Pregnancy Childbirth. 2008 Oct 30;8:48. PMID: 18973673

• Ultrasonic evaluation of fetal limb growth. Jeanty P, Kirkpatrick C, Dramaix-Wilmet M, Struyven J. Radiology. 1981 Jul;140(1):165-8. PMID: 7244221

• Nontraditional sonographic pearls in estimating gestational age. Gottlieb AG, Galan HL. Semin Perinatol. 2008 Jun;32(3):154-60. Review. PMID: 18482614

"This chapter focuses on nontraditional fetal ultrasound measurements, including the transverse cerebellar diameter, fetal foot length, ratios of biometric and nonbiometric measurements, epiphyseal ossification centers, amniotic fluid volume, placental grading, and other miscellaneous markers in the context of evaluating a fetus with possible intrauterine growth restriction."

Terms

• Crown-Rump Length (CRL)

• Functional linear discriminant analysis (FLDA) - new growth assessment technique using serial measurements to discriminate between normal and abnormal fetal growth.

• Gestational sac (GS) size

• Linear discriminant analysis (LDA) to longitudinal data (James and Hastie, 2001)

• Mean gestation sac diameter (MSD)

• Mean yolk sac diameter (MYD)

• Transvaginal scan (TVS)

• Termination of pregnancy (TOP)