Sonographic evaluation of the yolk sac in early in-vitro fertilization pregnancy and correlation with clinical outcome

During embryonic period the yolk sac is the primary source of exchange between the embryo and the mother. Beside the nutritive function, the yolk sac is the organ responsible for early erythropoesis and development of the part of the foetal gastrointestinal system.It also has endocrine, metabolic, immunologic, secretory and excretory function. Transvaginal sonographic visualisation of the yolk sac is possible approximately between the 22–32 days following in-vitro fertilization (IVF). Our goals were to determine the prognostic value of abnormal yolk sac size or shape at endovaginal sonography during the first-tr…