Assisted reproductive technology (ART) is a general term referring to methods used to achieve pregnancy by artificial or partially artificial means. The most frequently and currently practiced ART are IUI, IVF-ET & ICSI-ET.
Although Louise Brown- the first IVF baby was born to a natural cycles (without any stimulation) it was soon realized that the conception rate could be significantly improved if more than one eggs are available to work with. So Super ovulation-by controlled ovarian stimulation agents comprise one of the corner stone of the infertility management.
The different Assisted Reproductive Technologies are:
Ø IUI-Intrauterine Insemination
Ø Surgical sperm recovery techniques- like PESA, TESA, TESE, and MESA
Ø In Vitro Fertilization (IVF)-ET(Embryo Transfer)
Ø Cryopreservation of Sperms, Oocyte and embryos
Ø Other techniques like GIFT, ZIFT, etc are less commonly used now.
Superovulation: The aim is to obtain as many follicles as possible from which good quality eggs can be recovered. This is a basic need for all ART procedures.
IUI- Intrauterine Insemination: Semen sample is processed in the laboratory and injected into the uterine cavity .Placing the sperm in close proximity of the Oocyte enhances the chance of fertilization.
PESA, TESA and TESE
These are the surgical procedures used to retrieve sperms when there is obstructive Azoospermia (absence of sperms in the ejaculate).
PESA- (Percutaneous Epididymal Sperm Aspiration): With a 21 gauge butterfly needle and 10 ml syringe live spermatozoa is harvested by aspiration from epididymis.
TESA-(Testicular Sperm Aspiration): with a 19 gauge butterfly needle and 20 ml syringe spermatozoa is aspirated from the testes .It is undertaken if PESA – fails to recover motile sperms.
TESE– (Testicular Sperm Extraction): Here Sperms are collected out of the testicles after operation (testicular biopsy) – it is undertaken if the yield is inadequate by other techniques.
In Vitro Fertilization (IVF) - means fertilizing the egg and sperm outside the body by artificial means.
Beginning an IVF cycle is an exciting and anxious time for a couple. Our Center provides couples with the maximum amount of clinical, emotional, and administrative support they will need to complete their cycle successfully - whether it results in a pregnancy or not.
One complete IVF or ICSI cycle takes approximately 2-3 wks or more according to the protocol used and patient’s response. From Day 21 onwards patient is given daily injections and on Day 2 of the menses the stimulation of the ovaries starts by intramuscular or subcutaneous injections of a different hormone. The mean stimulation period is 12 days, depending on the reaction of the ovaries. The ovum pick up takes place within two days after stopping the stimulation (usually on day 13). Now the real IVF or ICSI follows in the laboratory. When fertilization occurs, embryos are transferred into the uterus (usually on day 15) and drugs supporting the uterus are given. After approximately 14 days a pregnancy test will show whether the IVF treatment has been successful or not.
The preparation for IVF /ICSI cycle needs counseling to explain the various steps involved.
To prepare the wife she needs to undergo blood tests to evaluate the hormonal levels, and baseline ultrasonography to assess the uterus and ovaries and then to take multiple doses of different hormonal injections. You may need to come for follow up on multiple occasions. According to the protocol used the number of injections needed varies .When the follicles are healthy and mature enough egg retrieval is planned .
What occurs during various stages of IVF?
a) Egg Retrieval through Puncture/Aspiration
If the last hormone blood test and ultrasound evaluation indicates healthy growth of follicles, then final maturation is induced with hCG injection and aspiration of mature follicles is planned after 36 hours. This entire retrieval procedure takes approximately 20 minutes performed under short general anesthesia. The physician locates each follicle through ultrasonic guidance and carefully aspirates them. The contents of the follicles are immediately taken to the IVF lab. Patients usually recover for one to two hours following Oocyte retrieval and are then discharged. Progesterone supplementation is initiated from the day of the retrieval.
b) Oocyte Culture, Insemination, and Fertilization
In the IVF laboratory, follicular fluid is examined under a microscope to locate all eggs, which are then incubated in a special media. Generally, semen collection occurs at about the time of the egg retrieval. The sperms are then added to the eggs in culture, here fertilization occurs. Any resulting embryos are stored in the incubator, and maintained in culture until the time of embryo transfer and/or Cryopreservation.
c) Embryo Transfer (ET)
Usually, transfer of the embryos takes place on day two to three post retrieval. The embryos are examined under the microscope and carefully aspirated to a thin transfer catheter. The loaded catheter is introduced under trans abdominal ultrasound guidance through the cervix into the uterus where the embryos are placed. This procedure takes a few minutes and does not require anesthesia.
After the transfer, the patient rests for two hours prior to discharge. Twelve days after the embryo transfer, a serum base pregnancy test is taken. During this period, patients are advised to perform light activity and remain in contact with the Center. If pregnancy does not occur, our team reviews the IVF cycle and makes specific recommendations for follow-up. The patient will speak with the clinical staff to review and if necessary, to discuss other options.
Intra Cytoplasmic Sperm Injection (ICSI)
Intra Cytoplasmic Sperm Injection (ICSI) is preferred to IVF in patients with severe male factor infertility. Instead of mixing the sperm with the egg here the embryologist utilizes a thin glass pipette to immobilize the sperm, sucks it up into the pipette, and then injects it up directly into the egg cytoplasm. Since the egg is the size of a pinpoint it is a sophisticated technique requiring high powered microscope , tiny glass pipettes , and instruments that translate hand movements into extremely fine movements of the pipettes .After sperm injection into the egg, further culture and embryo transfer is as with the IVF cases.
Indications for Intra Cytoplasmic Sperm Injection
Ø Asthenozoospermia – poor sperm motility
Ø Teratozoospermia – too many abnormal sperms
Ø Problems with sperm binding to and penetrating the egg
Ø Antisperm antibodies (immune or protective proteins which attach and destroy sperm) of sufficient quality to prevent fertilization
Ø Prior or repeated fertilization failure with standard IVF culture and fertilization methods
Ø Frozen sperm collected prior to cancer treatment that may be limited in number and quality
Ø Azoospermia with obstructive pathology.
What is the difference between IVF and ICSI?
The procedures till the egg collection are the same in IVF and ICSI .It is the laboratory aspects that differ .In ICSI we need to have a complex injection device to inject the sperm to the inside of the egg whereas in IVF the eggs which are collected into the dish are mixed with the sperms and left to fertilize by itself without injecting .ICSI is useful when the sperm parameters are severely impaired .
Cryopreservation
It is the technique low temperature preservation or freezing of the embryos , sperms, Oocyte or ovarian tissue for future use .Preservation and storage is done in liquid nitrogen at -196 °C.
Two different methods are slow rate cooling and vitrification.
Spermatozoa were the first mammalian cells to be successfully cryopreserved . Subsequently embryo cryopreservation was introduced .Oocyte cryopreservation has not yet reached the same stage .In 1983 for the first time live pregnancies were generated after transfer of cryopreserved human embryos. Since then embryo cryopreservation profoundly influenced the practice of clinical IVF .
Advantages –
Ø Reduces the wastage of valuable embryos
Ø Reduces the chance of multiple pregnancies
Ø Maximizes the number of conception attempts per stimulation cycle or Oocyte collection thereby decreases the need of repeated cycles of IVF treatment
Ø Significantly increases the cumulative pregnancy rate
Ø Reduces the health risk, inconvenience and cost
Ø Unexpected or to emergency situations like failed embryo transfer, patient illness, endometrial unsuitability, or any condition where implantation may be compromised can also be rescued by freezing the embryos.
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