![Elementary text-book of zoology. Yolk-sac. Embryo. miotic Cavity.. Yolk-sac. A, Stage of tbe Frog witb only small Yolk-sac ; B, Stage of the Skate ; ^, Stage of Developing Amnion ; Elementary text-book of zoology. Yolk-sac. Embryo. miotic Cavity.. Yolk-sac. A, Stage of tbe Frog witb only small Yolk-sac ; B, Stage of the Skate ; ^, Stage of Developing Amnion ;](https://c8.alamy.com/comp/RDGETW/elementary-text-book-of-zoology-yolk-sac-embryo-miotic-cavity-yolk-sac-a-stage-of-tbe-frog-witb-only-small-yolk-sac-b-stage-of-the-skate-stage-of-developing-amnion-d-stage-as-in-many-reptilia-the-amnion-and-serosa-are-not-completely-separated-cc-also-monotremata-e-a-typical-sauropsid-epiblast-is-represented-white-mesoblast-black-and-hypoblast-dotted-please-note-that-these-images-are-extracted-from-scanned-page-images-that-may-have-been-digitally-enhanced-for-readability-coloration-and-appearance-of-these-illustrations-may-not-perfectly-resemble-the-original-RDGETW.jpg)
Elementary text-book of zoology. Yolk-sac. Embryo. miotic Cavity.. Yolk-sac. A, Stage of tbe Frog witb only small Yolk-sac ; B, Stage of the Skate ; ^, Stage of Developing Amnion ;
![I am 7 weeks pregnant and in my ultrasound the yolk sac was visible but not the baby. Should I worry? - Quora I am 7 weeks pregnant and in my ultrasound the yolk sac was visible but not the baby. Should I worry? - Quora](https://qph.cf2.quoracdn.net/main-qimg-b87a1407c62c4f4e5a1aa0b134b8387b.webp)
I am 7 weeks pregnant and in my ultrasound the yolk sac was visible but not the baby. Should I worry? - Quora
![Supposed to be 7w but measuring 5.4 and only a yolk sac visible - July 2019 Babies | Forums | What to Expect | Page 2 Supposed to be 7w but measuring 5.4 and only a yolk sac visible - July 2019 Babies | Forums | What to Expect | Page 2](https://images.agoramedia.com/ugcphotoservice/100/2018/11/20/71125236/5c37f664-b209-4463-9fa1-3878e3cc6c13.jpg)
Supposed to be 7w but measuring 5.4 and only a yolk sac visible - July 2019 Babies | Forums | What to Expect | Page 2
![Predicting pregnancy failure in 'empty' gestational sacs - Nyberg - 2003 - Ultrasound in Obstetrics & Gynecology - Wiley Online Library Predicting pregnancy failure in 'empty' gestational sacs - Nyberg - 2003 - Ultrasound in Obstetrics & Gynecology - Wiley Online Library](https://obgyn.onlinelibrary.wiley.com/cms/asset/b8383736-63d9-4003-99be-f089d5c84b22/mfig001.jpg)
Predicting pregnancy failure in 'empty' gestational sacs - Nyberg - 2003 - Ultrasound in Obstetrics & Gynecology - Wiley Online Library
![Phil and Alex on Twitter: "I prayed for more than just a gestational sac (even though that's all we would need to see). Yolk sac made its first glimmer of appearance! I Phil and Alex on Twitter: "I prayed for more than just a gestational sac (even though that's all we would need to see). Yolk sac made its first glimmer of appearance! I](https://pbs.twimg.com/media/EF19V6QWsAUDaFH.jpg)