Invitro fertilization is an assisted fertilization technique. It involves the extraction of eggs from the woman and retrieval of sperm from the man. This is then fertilized manually in a laboratory dish and implanted back to the woman’s womb for continuous development of the embryo/embryos.
Invitro fertilization is used to assist infertile couples to conceive. The first successful birth of a child after IVF treatment, Louise Brown, occurred in 1978. In 2012 it was estimated that five million children had been born worldwide using IVF and other assisted reproduction techniques. The average success rate of IVF using own eggs starts to drop at about 30 and drops faster in the mid-30s and early 40s. The success rate of IVF in Nigeria is about 30% based on a study in a university hospital. In the US, the chances of having a life birth in women younger than 35years is 45%, 35-37years; 39.6%, 38-40 years; 28%, 41-42years; 15%.
Invitro Fertilization Process
It requires a pre-planned process. The patient is evaluated and some blood tests are carried out to know the hormonal profile of the patient. The uterus is also examined to rule out any structural problem (these problems should be corrected before proceeding with invitro fertilization). The risk factors and side effects are also explained to the patient. The process involves;
A woman’s eggs can be collected during natural ovulation; however, this makes the chances of fertilization to become much smaller. Therefore, the woman is given some injectable gonadotropins (usually FSH analogues) under close monitoring to cause hyperstimulation of her ovaries to produce more eggs than in her normal cycle. The estradiol level is monitored also the follicles that contain the eggs are monitored via ultrasound.
Retrieval of eggs
When the ovarian follicles have reached a certain degree of development, induction of final oocyte maturation is performed, generally by an injection of human chorionic gonadotropin (hCG). This is commonly known as the “trigger shot”. Ovulation occurs within 38-40 hours after this injection is given. The eggs are then collected via the vagina under ultrasound guidance. It can be done under general anaesthesia or conscious sedation. The process of collection lasts about 20-40 minutes. About 10-30 eggs can be retrieved.
Fertilization and implantation
The oocytes with the best chances are selected while the sperm is also washed and selected from the semen. They are both incubated in a culture media at a ratio of 1 ovum to 75000 sperms. In cases of poor sperm motility or low sperm count, a good and viable sperm is directly injected into the ovum. The resulting embryo is kept in a growth culture for 2-4 days before it is transferred to the woman’s uterus (womb). About 2-3 embryos with the best chances are implanted into the woman.
Blood test to determine pregnancy is done about 2 weeks after implantation while a scan is done about a month after implantation to confirm pregnancy.
Indications for in-vitro fertilization
Invitro fertilization helps couples who would have otherwise been infertile. Its indication includes;
- Blocked fallopian tubes; It can be done for women with bilaterally blocked tubes
- Male infertility; It can be done for men with low sperm count.
- Surrogacy; A woman with compromised uterus, structurally abnormal uterus of generally nit fit to carry a pregnancy can have her child from her eggs and have it implanted into another woman.
- Unexplained infertility; about 1 in 6 couples have fertility problems with uncertain diagnosis. They benefit from solutions such as IVF.
- Polycystic ovarian syndrome; patients with PCOS who have fertility issues can benefit from IVF.
- Elderly couple; women of older age have lower chances of conception due to low egg reserve. IVF is used to maximize the chances of conception in them.
- Premature ovarian failure: Women with premature ovarian failure or menopause can have IVF treatment using donor eggs, which typically has high success rates.
- IVF allows for pre-implantation genetic screening (PGS): PGS tests the health of the fertilized embryo by sequencing the DNA to determine if an abnormal chromosome is present. It also helps to prevent the transfer of genetic disorders.
- Embryos can be kept frozen for the woman to use in later years.
While the average couple may undergo 2 to 3 attempts with the IVF process before a successful pregnancy occurs, once you get pregnant, it is no different from a pregnancy established naturally. Also, IVF pregnancy is not considered high risk.