In Vitro Fertilization (IVF) is a form of Assisted Reproductive Technology or ART. It is a process of fertilization where matured eggs extracted from the ovary are combined with a sperm sample. It is a manual process carried out in test tubes within laboratories.
The IVF process involves fertilizing the egg outside of the body and later implanting the embryo into the uterus for conception.
Steps In IVF Procedure:
1. Ovulation Induction:
Ovulation induction is a fertility treatment that is administered by way of medication to induce ovulation to encourage the development and release of eggs from the ovary.
In case the subject is using her own eggs during IVF, she would then require commencing treatment with synthetic hormones to stimulate her ovaries to produce multiple eggs rather than a single egg that is produced every month.
The need for multiple eggs arises as not all eggs fertilize or develop normally for fertilization.
A subject might need the following medications for inducing ovulation;
2. Medication for Ovarian Stimulation:
An injectable medication containing follicle stimulating hormone (FSH) or luteinizing hormone (LH) or combination of both is administered to the subject to stimulate ovaries to produce more than one egg at a time.
3. Oocyte Maturation:
A medication named human chorionic gonadotropin (HCG) is administered to the subject after 8 to 12 days, when the follicles are ready for egg or oocyte retrieval. This is done to help the eggs mature.
4. Prevent Premature Ovulation:
These medications are administered to prevent the body from releasing premature eggs.
5. Prepare the Lining of Uterus:
The lining of the uterus is an important factor for IVF. The thickness of the lining of uterus also termed endometrium is essential for retrieving eggs or successfully implanting the embryo.
In instances where the lining is not receptive and thick enough for implantation, doctors may suggest the use of a medication called progesterone to make the lining of the uterus thicker and more receptive.
6. Egg Retrieval:
The process of egg or oocyte retrieval is carried out 34 to 36 hours after the subject has been administered human chorionic gonadotropin (HCG) and before ovulation. Doctors before carrying out the process of egg retrieval sedate the subject to minimize pain.
The eggs are retrieved from the subject through transvaginal aspiration meaning the process or retrieving eggs from the ovary. An ultrasound supervised probe is inserted into the vagina to identify the follicles.
A thin needle is then inserted through an ultrasound guide that penetrates the vagina and into the follicles to retrieve the eggs.
In instances where the ovary is not accessible through transvaginal aspiration, an abdominal surgery or laparoscopy may be advised. Abdominal surgery or laparoscopy also known as key hole surgery is carried by making a small incision around the navel.
A viewing instrument is then inserted through the incision to help guide the needles to the follicles to retrieve eggs. Eggs are retrieved from the follicles using suction.
Immediately after retrieving the eggs from the ovary they are placed in a special solution also called insemination media or culture medium.
Insemination media or culture medium is a nutritive solution that provides the retrieved eggs with the required nutrition to maximize the likelihood of successful fertilization of eggs by the sperm.
7. Sperm Retrieval:
The partner of the subject provides for a semen sample for the sperm to be extracted. The semen sample is required in the morning when the egg is retrieved.
For men who do not ejaculate the sperm can be directly retrieved from the testis using a surgical procedure. Donor sperms can also be utilized for the purpose.
There are two common methods used for fertilization
In this method the healthy sperm and matured eggs are mixed and incubated overnight.
b. Intracytoplasmic sperm injection (ICSI):
This method of fertilization is used when the semen quality or the number is a problem or in case of failed fertilization attempts in previous IVF cycles. ICSI requires the healthy sperm to be directly injected into each mature egg.
9. Embryo Development:
Embryo development or embryogenesis is the process by which the assimilation of sperm and mature egg develops into an embryo.
10. Assisted Hatching:
In many instances of IVF treatment, the process fails because the embryo is unable to implant in the uterus. The embryo detaches from the outside membrane called the zona pellucida after 5 to 6 days of fertilization.
Immediately after hatching the embryo implants itself in the uterus. For women who have experienced unsuccessful IVF attempts, doctors recommend assisted hatching.
Assisted hatching is a technique by which a hole is made in the zona pellucida just before transfer for the embryo to successfully hatch and implant in the uterus.
11. Preimplantation Genetic Testing or PGD:
PGD is a procedure carried out before implantation of an embryo to check if the embryo has any defects.
This is done to ensure that no genetic disorders or abnormalities are passed on to the child. While PGD is carried out as a preventive measure, it cannot be considered a safeguard.
12. Embryo Transfer:
Embryo transfer pertains to the transferring of embryos into a woman’s uterus to encourage pregnancy.
The process takes place after 2 to 5 days from egg retrieval.
The subject is administered mild sedatives and may experience mild cramping A long flexible tube called a catheter is inserted into the woman’s vagina, running through the cervix into her uterus. A syringe containing one or more embryos is attached to the catheter and is transferred to the woman’s uterus by the doctor.
13. Embryo Cryopreservation:
Embryo Cryopreservation or embryo freezing is a process carried out by most IVF programs. It is a process by which healthy embryos are stored at sub zero temperatures for use later.
Women who fail to conceive in earlier attempts can use these embryos for pregnancy instead of going through the complete IVF cycle. It can also be utilized for embryo donation for women wishing to conceive.
After the Procedure
While women can carry on with their day to day routine it is advised that after the implantation of embryos women do not over exert themselves physically.
- Discharge of small amounts of clear or bloody fluid can occur owing to the swabbing of the cervix before the transfer of embryo.
- High estrogen levels may cause breast tenderness.
- Mild bloating or cramping may exist.
In cases of severe pain after the embryo transfer subject is advised to visit the doctor to negate complications such as infection, twisting of an ovary and severe hyper stimulation syndrome.