The yolk sac plays an important part in the early stages of pregnancy. Find out what it does and how it works. ... This may be before they are even able to see the fetal pole, ...

No yolk sac or fetal pole by 6 weeks. Heavy bleeding or sharp pelvic pain occurs. Previous scans showed a heartbeat that’s now absent. Steps to Take If There’s No Heartbeat.

fetal pole; yolk sac; A gestational sac is the sac of water containing the fetus. Afetal pole means that the arms and legs developed to variable extents, depending on gestational age.

When 15-day fetal mouse duodenum is cultured in presence of half of the human yolk sac (HYS), villi and crypts differentiate in the duodenal segments. It appears that HYS also has a CDF activity.