Assisted reproductive techniques: The journey so far by Prof Oladapo Ashiru
Over forty years ago, the study of in vitro fertilisation began, and for the first time in the history of medical science, a woman named Lesley Brown, considered to be sterile at that time due to her diagnosis of primary infertility secondary to tubal occlusion for about nine years, on July 25, 1978, gave birth to a baby girl called Louis Brown (whose name has been recorded in history as the first successful IVF baby) with the team of British doctors of Robert Edwards (a Nobel Prize winner and IVF pioneer) and the late Dr Patrick Steptoe. July 25, is now regarded as World ART Day. With over eight million IVF births in the world since the first successful IVF procedure, there have been beams of hope in the heart of couples who were initially considered as being infertile or sterile. From being viewed as just an experimental procedure to the first successful IVF procedure involving non-stimulation of the ovaries, laparoscopic retrieval of a single oocyte following the natural cycle, single embryo transfer; IVF has evolved into a beautiful unfolding and yet not wholly unfolded procedure. Shortly after this, several achievements have been recorded in countries like Australia and the United States of America, some of those significant achievements in the 20th century are listed below:
- 1980, the first IVF birth recorded in Australia.
- 1981, the first IVF world congress took place in Bourn Hall England and the first IVF birth recorded in the USA.
- 1982, the first IVF birth recorded in France.
- 1983, the first IVF birth using donated oocytes and cryopreserved embryos.
- 1984, GIFT (Gamete Intra-Fallopian Transfer) was introduced.
- 1987, the transvaginal ultrasound oocyte retrieval.
- 1988, MESA (Microsurgical Epididymal Sperm Aspiration) procedure was first used and named.
- 1989, the first IVF was born in Nigeria, Sub-Saharan Africa.
- 1990, preimplantation genetic diagnosis was introduced for sex-linked diseases.
- 1991, ICSI (Intracytoplasmic sperm injection) was successfully achieved, and the baby was born the following year.
- 1993, the first IVF baby born by using TESA (Testicular sperm aspiration).
Reproductive clinicians and researchers have come up with newer and better procedures that can increase the success rate and also improve the quality of health care in this field of medicine. Some of the methods will be briefly discussed in this article ranging from ovarian stimulation to procedures developed for the prevention of hereditary conditions on the embryos of affected couples, ongoing research, and prospects in vitro fertilization. It is also essential to state that though the primary aim of IVF was to reduce infertility to its barest minimum, the objectives of IVF have become endless as couples who are fertile but want particular sex or are both carriers of sickle cell anemia or wants multiple births have also benefitted greatly.
The 40 year-old wonder is now extensively referred to as “Assisted Reproductive Technology,” which can be defined basically as medical procedures and innovations for addressing primarily the issue of infertility. IVF is now listed among the processes used in ART; others are ICSI, Assisted Hatching (AH), PGT, blastocyst transfer, frozen embryonic transfer, donor conception, cryopreservation, GIFT, ZIFT, among many others.
- Ovulation induction:This is the artificial stimulation of the ovaries to produce oocytes in women that cannot produce oocytes naturally. It is done by instigating an ovarian cycle and the administration of Follicle Stimulating Hormone and Gonadotropin-Releasing Hormone drugs or injections for the production of follicles and the release of oocytes from the ovaries.
- Intrauterine insemination (IUI):This method involves injecting the sperm directly through the woman’s cervix into the uterus just before or at the time of ovulation. This option is considered if the woman has gone through examination by the physician and has been certified to have a normal healthy uterus and fallopian tube. The diagnosis for the cause of infertility, in this case, could be as a result of low sperm motility or sperm count; also if the above condition is met, the male partner might be unavailable due to distance or before cancer treatment, then IUI can be used. IUI is also known as artificial insemination.
- ICSI: It is a standard clinical procedure used to introduce a single sperm cell into the cytoplasm of the oocytes for fertilization by the manual use of a micromanipulator. ICSI is mostly done in the case of male infertility with conditions like poor motility of sperm cells, low sperm count, the inability of the sperm to penetrate the zona pellucida of the oocyte, and other related conditions. Fertilisation is evident when there is a formation of two pronuclei. This method has been beneficial over the years, with about 70 per cent of couples opting for it.
- Assisted Hatching:It is a micromanipulation technique that is carried out before the embryos are placed in the uterus following the IVF or ICSI cycle that helps the embryo to hatch from the zona pellucida. During the first five to seven days of fertilisation, the embryos have a protective outer layer called the zona pellucida, which sometimes doesn’t hatch in some women hence causing difficulty in implantation of the embryo(s).
- Preimplantation Genetic Testing (PGT):It is designed to check for genetic and chromosomal defects in embryos created by IVF before the transfer of the embryos, it reduces to the barest minimum miscarriages, implantation failures due to genetic abnormalities. There are different forms of PGT; PGT-A is used to check for embryos with abnormal (extra and missing) chromosomal number and also for sex determination for family balance. PGT-M is used to check for embryos with single gene disorder like sickle cell anemia; PGT-SR is used to check for embryos with a defect in the structural arrangement of the chromosomes.
- Donor conception: This occurs when either the female or male partner cannot produce oocytes or sperm cells on their own or in both cases due to congenital anomalies, or surgical removal of the organs involved or untraceable causes. This is becoming more and more acceptable by most couples today as near donor matches for colour, height, blood group, genotype, and fantastic family history are used during donation.
- Surrogacy: This is a form of ART in which a woman carries a baby for another person or for a couple. Most times surrogates are injected with embryos from the sperm and oocyte of the couple in question or a near match donor sperm and oocyte. It is fast becoming popular with ethical limitations in some countries.
- Cryopreservation:This is a method used to freeze eggs, embryos or sperm for use in IVF. Eggs and sperm cell can be thawed for use whenever there is a need for it. Thawed sperm can be used for IUI while frozen embryos reduce the recurrent infertility treatment cycle. Cryopreservation also helps for preservation as the name implies in couples or persons that are not yet ready for pregnancy. One of the latest forms of cryopreservation is the ovarian tissue cryopreservation, also called ovarian tissue banking or freezing, where a part or all of an ovary is removed, and the tissue that contains the eggs is cut into thin slices and frozen. Generally, cryopreservation is useful for couples who need to undergo specific treatments that might lead to the loss of ovaries or testes like cancer treatments.
- Management of Reproductive Endocrine Disruptors: One cannot overemphasise the detrimental role that toxins play on our reproductive health. Such toxins from the environment and in the food we eat include heavy metals, toxic chemicals, and pathogens. They are called endocrine disruptors. WHO and FIGO now know that removal of such ED through lifestyle changes and use of specialised detoxification methods can help to improve the success of IVF. (Ashiru et al. Global Reproductive Health 2019).