Implantation Endocrinology of Pregnancy Flashcards
Bottom layer of endometrium
basalis layer (1/3 of full thickness) –> not shed during menses –> contains epithelial, stromal, and vascular progenitor cells for proliferation and neovascularization of endometrium during proliferative phase under estrogen regulation
Top 2/3 of full thickness endometrium shed during menses
Functionalis layer
Is there a change in endometrium thickness during the secretory phase?
No
The key hormone during proliferative stage
estrogen
What are the minimal endocrine nees for normal cycling of the endometrium?
estrogen priming then progesterone
The period of endometrial maturation which permits the attachment of the embryo and the establishment of pregnancy.
endometrial receptivity
What maintains the early pregnancy?
corpus luteum stimulated by fetal hcg to release estrogen and progesterone
What is the window of implantation in the human?
days 20-24
At what stage of embryo development implantation occurs?
blastocyst
How can a “5” cell or “3” cell embryo exist?
asynchronous division
how many days does it take before implantation occurs?
6-7
Which phase of implantation? hatched blastocyst is positioned in apposition to the endometrial epithelial cells
apposition
Which phase of implantation? the trophoblast cells adjacent to the inner cell mass adher to the apical surface of the endometrial epithelial cells
adhesion
Which phase of implantation? the trophoblast cells insinuate themselves in between the endometrial epithelial cells
intrusion
Which phase of implantation? the trophoblst cells and ultimately the whole embryo invade through the basement membrane and the endometrial stroma and reach and invade into the maternal vessels
invasion
The embryo becomes fully embedeed in the endometrium by day ____ post ovulation
12-14
Implantation usually occurrs at the mid ____ endometrial surface
posterior
Enzymes involved in implantation
MMP-9 collagenase, urokinase type plasminogen activator
During implantation and placentation there is invasion of the ______ and remodeling through secretion of ____
maternal stroma and blood vessels through secretion of ECM
Is invasion of embryo comparative to invasive activity of a neoplasm?
No –> trophoblast invasion is regulated with specific factors in trigger and arrest of the process
____ cells invade maternal spiral arteries of the endometrium and replace the endothelial cells
trophoblast
direct contact of maternal blood with trophoblastic chorion
hemochorial placentation
At the core of each chorionic villus, there are fetal capillaries adjacent to the trophoblast layer and coalesce to form ____
umbilical vessels
Fusion of cytotrophoblasts results in formation of ____
syncytiotrophoblast layer
On the inside of each villus is a ____
fetal capillary
Trophoblastts are derived from the _____ of the blastocyst
trophectoderm
Endocrine trophoblast functions
hcg and p4 (and E) secretion by syncytiotrophoblast + exchange of nutrients and gases between mother and fetus
T/F cytotrophoblasts secrete hcg
F –> only syncitiotrophoblasts
T/F extent of trophoblast invasion can cause pathological situation
T –> preeclampsia, intrauterine growth restrictionk, preterm birth, maternal mortality
