Hello, I'm Irit Granot.
I am a senior embryologist.
I am the technological and quality assurance manager of the IVF lab,
at the IVF unit, Herzliya Medical Center.
The topic of my talk is "protocols for uterine preparation for implantation."
Implantation of the embryo in the uterus
is crucial for establishment of successful pregnancy.
The preparation of the endometrium for implantation is hormone-dependent.
The pituitary gonadotropic hormones, FSH and LH,
stimulate the ovary to secrete the sex steroids estrogen and progesterone,
which regulate the morphological and functional changes
that are involved in acquisition of endometrial receptivity.
Estrogen, which is mainly secreted during the first half of the menstrual cycle,
induces the proliferation of the endometrial cells.
Therefore, this period is referred to as the proliferative phase of the cycle.
Progestrone, which is the predominant sex steroid in the second half of the cycle,
induces the differentiation of the endometrial cells to form the decidua,
the receptive tissue for the implanting embryo.
This half of the cycle,
known as the secretory phase,
is characterized by the formation of large secretory endometrial glands,
which secrete high amounts of cytokines and growth factors,
as well as vascularization,
infiltration of the endometrium by a variety of immune cells from the blood stream,
swelling of the tissue by a localized increase in vascular permeability,
and development of tissue edema.
The uterus becomes receptive during the mid-secretory phase
for a limited period that spans 7-10 days after the LH surge.
In a 28-day cycle,
it is between days 19 and 23 of the cycle.
This period is commonly known as the window of implantation.
Implantation can only take place during the window of implantation.
Human embryo implantation is a three-stage process