title: Transvaginal sonography of the yolk sac in normal and abnormal pregnancy.
abstract: A cross-sectional study comprising 117 consecutive first trimester singleton pregnancies was performed using transvaginal sonography (TVS) to evaluate size abnormalities of the secondary yolk sac (YS) vis-à-vis pregnancy outcome. In normal pregnancy outcome (NPO) the YS diameter showed an increase from the 5th to the 11th week, menstrual age, followed by a decrease and its disappearance after 12 weeks. A YS of abnormal size was statistically significant (p < 0.001) in spontaneous abortion (SA) versus NPO, with a sensitivity of 68.7%, a specificity of 99%, a positive predictive value of 91.6% and a negative predictive value of 95.2%. These preliminary results indicate that a measurement of the YS very early in gestation may be a useful marker of pregnancy outcome.
authors.affiliation: University ¿La Sapienza¿, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Stampone
authors.forename: M
authors.initials: M
authors.lastname: Nicotra
authors.forename: C
authors.initials: C
authors.lastname: Muttinelli
authors.forename: E V
authors.initials: EV
authors.lastname: Cosmi
mesh_terms: D000022:Abortion, Spontaneous / Q000000981:diagnostic imaging; D015415:Biomarkers; D003430:Cross-Sectional Studies; D005260:Female; D005544:Forecasting; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011379:Prognosis; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal; D015017:Yolk Sac / Q000000981:diagnostic imaging*
chemical_list: D015415:Biomarkers