Lecture notes on implantation

Implantation:

Definition: The process during which the blastocyst attaches to the endometrium and subsequently embeds in it.

It occurs at 6 days after fertilization and

by the 11 th to 12^th days of development the blastocyst is completely embedded in the endometrial stroma.

Bleeding may occur at the implantation site as a result of increase blood flow into the lacanar spaces.

 This bleeding occur near the 28^th day of menstrual cycle, it may confused with normal menstrual bleeding.

Q: In which phase of menstrual cycle implantation is occurred?

Ans: The secretory phase, during which time uterine glands and artery become coiled.

What are the phases of menstrual cycle?

1.      Menstrual phase

2.      proliferative(follicular)  phase

3.      secretory (progestational) phase

What is ovarian cycle?

It is a regular monthly cyclic changes in the ovaries (which start at puberty )

Phases are:

i)                    follicular development

ii)                  ii) LH surge (ovulation)

Normal sites of implantation: The blastocyst implants in the endometrium along the anterior or posterior wall of fundus of uterus. (Trophoblast cells of blastocyst invade the epithelium and underlying endometrial stroma with the help of proteolytic enzymes.)

Abnormal implantation:

1.      implantation in abdominal cavity

2.      implantation in the pouch  of Douglas

3.      implantation in the ampullary region of f. tube (most common)

4.      Implantation in the internal os

5.      Ovarian implantation

6.      Interstitial implantation

7.      Tubal implantation