The Yolk Sac. An interesting small structure of the human embryonic stage.

The yolk sac is a small extra embryonic structure that plays a crucial role during the first trimester of pregnancy. It provides nutrients, endocrine, metabolic and hematopoietic functions during embryogenesis reaching its peak of functionality between the 4th and 7th week of embryonic life (1). The size of the yolk sac ranges between 2 and 5 mm and continues to growth up to the 10th week of gestation. Abnormalities of the yolk sac are correlated with poor pregnancy outcomes (2, 3). Transcervical hysteroscopic embryoscopy is gaining an important role in the evaluation of the patient with first trimester pregnancy loss.
Source: The Journal of Minimally Invasive Gynecology - Category: OBGYN Authors: Tags: Images in gynecologic surgery Source Type: research