What is IVF and when is it recommended?

Conventional IVF involves the removal of the oocytes from the ovaries, followed by the fertilization process, by introducing motile spermatozoa into a special culture medium, where the oocytes are located. Following fertilization and development of the embryos in the laboratory, the embryos are then transferred into the uterine cavity, a process called Embryo Transfer. IVF is an in vitro technique that essentially attempts to mimic the biological processes in vivo.

IVF can help overcome many causes of infertility, such as in cases of blocked or damaged fallopian tubes, couples whose infertility is unexplained and/or in the case of mild sperm problems. Other factors like age, endometriosis, immunology, obesity and bad psychology may lead a couple to infertility and consequently, to IVF treatment.

What are the stages of IVF?

 There are 4 main stages of IVF:

  1. Follicular development and monitoring

In a normal menstrual cycle, LH and FSH are hormones that stimulate development and maturation of a single oocyte.  In order to optimize pregnancy rates during IVF, the ovaries are stimulated using higher levels of the stimulating hormone that naturally exists in the body; ovulation induction requires the use of Gonadotrophin injections. The aim is to have more than one mature oocytes available for fertilization.

Many different stimulation regimes exist and the physician will choose the protocol best suited to the patient, based on her medical history, cycle and age. Close monitoring of the follicles, where the oocytes grow, is required and involves frequent ultrasound scans to determine their size and number. For the final maturation of the oocytes, an additional hormone will be administered. Based on the timing of this final injection the timing of the oocyte recovery is determined.

Alternatively, during a Natural cycle-In Vitro Fertilization (NC-IVF), ovarian stimulation is not required. The single predominant follicle that grows naturally is monitored and a single oocyte is recovered.  

  1. Oocyte recovery (egg collection)

The procedure is performed transvaginally and requires anaesthesia (intravenous sedation).  A needle is advanced under ultrasound guidance through the upper portion of the vagina into the follicles within the ovary. The follicular fluid is aspirated in tubes that are then taken to the laboratory; the oocytes are identified, transferred into culture media and stored in an incubator to continue the maturation process until the time of fertilization. 

  1. Oocyte fertilisation

The semen sample is processed and used for the fertilization of the oocytes. The sample can be fresh, (provided by the partner on the same day as the egg collection), frozen (previously stored by the partner or in the case of donor sperm) or following a testicular biopsy (in cases of azoospermia). Approximately 100,000 motile spermatozoa are added per oocyte, 2-5 hours after oocyte recovery. This method of insemination is the least invasive method for the oocytes.  Fertilization will occur in the incubator, within the next 12-18 hours.

The following day the embryologist will perform a fertilization check and the normally fertilized oocytes will be cultured on. The resulting embryos are allowed to develop for 2-6 days, at which point they will develop into blastocysts. Their development is closely monitored and recorded.

  1. Embryo transfer

This procedure involves the selection of the embryo(s) to be transferred, which are loaded into a small, thin catheter that is inserted by the clinician through the neck of the womb into the uterine cavity. The procedure does not normally require anaesthesia, it is painless and takes only a few minutes.

The number of embryos to be transferred depends upon parameters, such as the woman’s age and medical history and the developmental stage and quality of the embryos/blastocysts. Furthermore, the possibility of a multiple pregnancy, resulting from the transfer of more than one embryos must be taken into account. The clinic’s scientists and clinicians are always available to discuss any concerns regarding the number of embryos to be transferred. A short resting period in the recovery room following the transfer and restrictive activities for the rest of the day are usually recommended.

The day after oocyte retrieval, progesterone and other supplements will be prescribed to ensure that the lining of the uterus receives sufficient stimulation and sustains the implantation of the embryos. Quantitative pregnancy test performed using a simple blood test (to detect the β-chorionic gonadotrophin hormone), is done approximately 13 days after the embryo transfer procedure.