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The Endowment for Human Development
The Endowment for Human Development
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Slideshow: Slideshow 1

Three-Cell Embryo

#42, Slide 3 of 19

40 hours

Source: Centro Riproduzione Assistita, Catania, Italy.

Label Key:

1. blastomere #1
2. blastomere #2
3. blastomere #3
4. perivitelline space
5. zona pellucida
6. polar body
All ages referenced to fertilization, not last menstrual period.
Fertilization BeginsThree-Cell EmbryoEarly BlastocystImplantation Well UnderwayThe 4-Week EmbryoVitelline Vessels and Yolk SacHand Plate and Vital OrgansHand, 7 Weeks Pregnant7½-Week EmbryoRight Eye and Facial Profile9-Week Fetus, MRI AnimationExit Stage LeftPosterior Surface of Left ThighStill HidingThe MouthFace, 27-Week FetusFace and Left ForearmReady for Birth and Beyond
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