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Updated: Aug 2, 2026
10:59
Human Blastocyst Biopsy and Vitrification
Published on: July 26, 2019
Does "blastocyst estrogen" initiate implantation?
Science (New York, N.Y.)
|February 18, 1977
Summary
Early pregnancy involves a blastocyst factor that increases capillary permeability. This factor is likely estrogen, synthesized by the blastocyst, aiding implantation.
Area of Science:
- Reproductive biology
- Endocrinology
- Developmental biology
Background:
- Capillary permeability changes are crucial for embryo implantation.
- The specific factors influencing these changes during early pregnancy are not fully understood.
Purpose of the Study:
- To investigate the role of blastocyst-secreted factors in altering uterine capillary permeability.
- To determine if estrogen plays a role in early pregnancy-induced capillary permeability changes.
Main Methods:
- Fertilized rat eggs were incubated with estradiol-17beta.
- Eggs were transferred to pseudopregnant rat uteri on day 5.
- Capillary permeability was assessed locally around the transferred eggs.
Main Results:
- Eggs incubated with estradiol-17beta induced a local increase in capillary permeability.
- Control eggs without estrogen did not induce this permeability change.
- This suggests a role for estrogen in mediating early pregnancy-induced vascular changes.
Conclusions:
- The blastocyst factor responsible for increasing local capillary permeability during early pregnancy is likely estrogen.
- Estrogen synthesized by the blastocyst may facilitate embryo implantation by modulating the uterine environment.
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