In vitro Fertilization (IVF) and Embryo Transfer (ET) literally means “fertilization outside the body” compared to in vivo fertilization which is “fertilization within the body”
The basic principle of IVF is removal of eggs from the ovary, their fertilization in the laboratory and subsequent placement of the resulting embryos in the uterus.
After years of successful use and refinement IVF is now recognized as a safe, effective and a “first line” fertility treatment for many couples. IVF is offered to nearly all the couples where other treatments have not helped, but is the only choice in women with blocked, nonfunctioning fallopian tubes
Who Needs IVF
IVF is indicated in patients with patients with blocked, nonfunctioning fallopian tubes, Ovulation disorders, male factor infertility, Poly cystic ovarian syndrome (PCOS), endometriosis and unexplained infertility.
Steps of IVF Procedure
1. Controlled Ovarian Stimulation
After pretreatment evaluations, the couple attends the IVF center seven days before the onset of the periods (21st day of the ongoing cycle) to start the down regulation and then on the 2nd day after the onset of the menstruation of the desired menstrual cycle to begin the treatment. The complete treatment takes up to 25 days counting from the start of menstruation.
The ovaries are stimulated by the gonadotrophin injections to produce multiple follicles so that the increased number of eggs can be collected. Gonadotrophins are administered for 10-12 days. Some resistant cases take longer to respond. Careful monitoring is done through vaginal ultrasounds and blood hormone tests. The follicle diameter, their number and endometrium thickness are also noted. Depending on the response, the dose is maintained, increased or reduced. When the desired values of follicle diameter, endometrium thickness and serum estradiol are obtained, hCG trigger is given. Egg retrieval is scheduled 36 hours after hCG administration.
Egg retrieval (ER) and Insemination
Egg retrieval (ER) is a minor surgical procedure that takes about half an hour. It can be performed under short acting intravenous or local anesthesia. Light general anesthesia is usually used for the comfort of the women. It is done 36 hours after hCG injection. Retrieved eggs are placed in Petri dishes containing culture medium & allowed to remain there undisturbed for 2-5 hours till specially-processed sperm are added. After 18-20 hours of sperm insemination the oocytes are assessed for fertilization.
Following fertilization on day 1, cleavage of eggs takes place to form the embryos, which are cultured for 3-5 days. The laboratory provides an efficient, sterilized and safe transitional environment for oocytes from follicular aspiration until embryo transfer
2. Embryo Transfer (ET)
Embryo Transfer is a simple procedure that does not require anesthesia, the patient lies in lithotomy position with full bladder, and cervix is exposed through a bivalve vaginal speculum. A delicate special plastic catheter is introduced through vagina and cervix into the uterus and placed with its tip in uterine cavity. The embryos are then transferred through the catheter. Best embryos are selected on the basis of cell number and morphology for embryo transfer or for freezing to utilize in Frozen Embryo Transfer (FET).