03/03/2018
INTRODUCTION TO IN VITRO FERTILIZATION (IVF)
1. INDICATIONS FOR IVF
Assisted reproduction technology encompasses several techniques to by-pass the problems preventing conception through the normal s*xual in*******se in a stable relationship. The commonest assisted reproduction method is IVF. This refers to the assemblage of procedure culminating in the retrieval of human oocyte(eggs) which is approximated to potentiated s***matozoa in a test tube (In vitro) in a laboratory condition equilibrated to the same physiological condition as obtains in the normal human environment (in vivo, within the womb). It thus involves fertilization outside the human body and without s*xual in*******se.
In vitro Fertilization (IVF) has enhanced the possibility of pregnancy even in situations thought to be impossible until four decades ago when the first baby, Louisa Brown in Great Manchester City, United Kingdom, was born using this technology.
When selecting cases for IVF, initial diagnostic approach is directed at separating absolutely infertile patients from potentially fertile ones. For example, in cases of bilateral blockage of the Fallopian tubes that is not repairable, refractory (not responsive) anovulation (absence of ovulation), absence of motile s***m or very low s***m count, the couple is absolutely infertile and IVF is the only option.
Those who are potentially fertile are treatable by artificial insermination(IUI) but may fail to conceive after a period of time, appropriate for their age( due to defective egg, s***m, or embryo; patent but malfunctioned tubes; failure of fertilization), IVF is the only alternative as there are no tests to confirm these barriers.
Female Factor
The female is said to have the problem in 30% of cases of infertility, the male also in 30% while 20% is from contribution by both parties. The commonest cause of infertility, particularly in our environment is tubal problems and most patients requiring IVF suffer from tubal disease. Tubal surgery is usually not an effective especially where there is peritubal adhesions, thickening of the tubal wall, irrepairable damage to the ciliary epithelium within the tubes, and severely damaged fimbria (ends) of the tube. When there is pathological swelling of one or both tubes, Hydrosalpinx, may result in 50% decline in implantation rate during IVF and may require surgery prior to the procedure. A high level of chlamydial antibody indicates tubal disease as Chlamydia can present as an asymptomatic infection while causing silent ciliary damage in the tubes.
Chances of successful IVF are less in abnormally shaped uterine cavities than in a normally shaped small uterine cavity. Hence fibroid encroaching into the uterine cavity should be removed prior to IVF.
Another condition that may require IVF is endometriosis, a situation where active endometrial tissues (Tissues that line the womb of a woman) are found anywhere other than the endometrial cavity. In this condition, the IVF results are similar no matter the severity of the condition, and the success rate is less than that of women with tubal factor.
Age is a major determinant of fertility outcome. This is due to the waning ovarian that is associated with aging. In advanced ovarian age, as detected by increased cycle day 3 FSH(Follicle Stimulating Hormone) or Estradiol levels, there is reduced IVF outcome and egg donation or modified IVF stimulation protocols are alternatives.
Male factor
If the total s***m count is < 10million, s***m motility is < 30%, or there is abnormal s***matozoon morphology >60%, IVF is indicated. In severe male factor infertility, either of the obstructive or non-obstructive type, micromanipulation techniques can be used with IVF to achieve pregnancy.
In the presence of antis***m antibodies, if there is no conception with immunosuppressive drugs, use of condoms and IUI patients are advised for IVF.
In unexplained infertility, if the patient fails to conceive after 6 cycles of IUI and superovulation(use of drugs to increase the number of follicles that get to maturation in each cycle), or if the woman is greater than 35 years, IVF is advised.
IVF gives better results in young women and success declines in women greater than 40 years due to oocyte problems like genetic or chromosomal defects. Age factor therefore should be kept in mind while selecting cases for IVF.
Good physical and emotional condition of the patient improves success rate because of better response to medication. If there is an existing medical condition, life diabetes mellitus, kidney or liver diseases, prior consultation with a medical specialist is necessary.
In certain situations like premature menopause( Menopause before the age of 40 years), when there are genetic disorders, following radiation therapy, or if the ovaries are not available for pickup due to adhesions, parenthood is possible using donor egg or embryo.
Finally, alternatives to IVF exists and must be considered. Surrogacy and adoption are veritable options that should be offered to couples in the face of repeated IVF failures or where IVF is not possible or the results are considered suboptimal.
