IVF ICSI And Assisted Reproductive Technologies
The inability to conceive comes as a surprise to most couples, many of whom assume that pregnancy will follow immediately on discontinuing contraception. And the inability to conceive in-spite of 6 months of unprotected sexual intercourse is termed as infertility. Because, within any given month, the chances of achieving a pregnancy in a fertile couple is about 15%. For many couples, they will conceive through treatments and medications to correct ovulatory dysfunctions or some may need surgery to correct anatomical problems. And for some couples, they may require more involved medical procedures, like In Vitro Fertilization which are designed to increase the number of eggs & or sperms or bring them closer together, thus improving the likelihood of pregnancy.
In Vitro Fertilization, Intra Cytoplasmic Sperm Injection
They are the most popular treatments for successful fertilization. They are identical procedures apart from the way the egg is fertilized. In-Vitro Fertilization allows sperms to penetrate the egg on its accord whereas Intra Cytoplasmic Sperm Injection (ICSI) directly inserts the sperm into the egg. In Vitro Fertilization was originally developed to overcome blocked tubes but now In Vitro Fertilization / ICSI are used to treat a variety of indications.
Stage 1: Ovarian Stimulation & Monitoring:
Stimulation to produce multiple mature follicles to maximise chances for successful fertilisation. By increasing the number of eggs for fertilisation & transfer, it is hoped that at least one will result in a pregnancy. So about 5 – 10 follicles are grown by using either FSH or a combination of FSH/LH. The dosage and no. of days of stimulation depends on the ovarian response. In addition to this, medications are used to control timing of ovulation for egg recovery. And HCG is is given to release the egg. And egg retrieval is arranged just prior to expected ovulation.
- It is important to note that there is not an egg in every follicle.
- The response is monitored by ultrasound and blood tests .
- Through USG one can know the follicle growth, size & no.
- Estradiol (e2) is used to monitor optimal timing of administration of HCG.
Stage 2. Egg Retrieval:
Recovery of as many as mature eggs as possible is done, usually 36 hrs after HCG. Under ultrasound guidance, accurate aspiration of eggs where needle is guided into each follicle and contents are withdrawn. After recovery, contents are transferred in a sterile temperature controlled container for an attempt to fertilise them.
Stage 3. Fertilization:
On the same day as OPU, semen from the male partner is required. After sperm washing, if In Vitro Fertilisation (IVF) is chosen, sperms & eggs are placed together in the laboratory and incubated at the same temperature as the female body. In Intra Cytoplasmic Sperm Injection (ICSI), eggs are prepared for injection & maturity identified. Eggs are placed on a holding pipette and single sperm is injected with an injection needle into the cytoplasm of the egg, fertilisation is identified 20 – 24 hrs later.
Stage 4 .Embryo Development:
Most transfers take place between day-2 & day-5. Assessment of embryo cleavage and then making sure the embryo is progressing and is capable of resulting in a pregnancy.
Stage 5. Embryo Transfer:
Embryo are placed in a catheter and transferred into the uterus via the vagina.
Cryopreservation: If any remaining embryos are there after transfer, they can be stored & frozen by a process called cryopreservation. An advantage is the likelihood of pregnancy can be improved. The entire process up to fertilisation need not be repeated and also multiple pregnancies are reduced .
Stage 6. Luteal Phase Support:
Mainstay of treatment is to ensure that there is adequate progesterone present. HCG injections or progesterone pessaries and gels are continued till the outcome of the cycle is known.
Success rates: 25 to 40 %
Benefits: Fertilisation and embryo cleavage is known. Blocked tubes are overcome.
Limitations: Low success rates and Multiple pregnancies.