Blastocyst Implantation & Gastrulation
Educational content only — not medical advice.
Embryonic Age: 1 weeks post-fertilization — The blastocyst implants into the uterine endometrium, initiating the three primary germ layers that will form all tissues and organs.
Biometric Measurements
- Approximate Length: 0.2 مم (CRL/CHL - INTERGROWTH-21st)
- Estimated Weight: < 0.01 جم (Hadlock)
- Fundal Height: 7 cm
- Size Comparison: Microscopic seed
Key Fetal Milestones
- Formation of bilaminar and trilaminar embryonic disc
- Appearance of the primitive streak and notochord
- Trophoblast proliferation establishing early uteroplacental circulation
Maternal Changes
Rapidly rising hCG and progesterone levels; spiral arteries in the uterine endometrium remodel to nourish the conceptus.