In vitro fertilisation involves taking mature egg cells from the woman, fertilising them with spermatozoa in a laboratory, and transferring the resulting embryos back to the uterus two to five days after fertilisation. The procedure is the treatment of choice for women with damaged, blocked or missing uterine tubes. Alongside this, IVF is also used in cases of infertility with unclear reasons, endometriosis, pelvic inflammatory disease, early depletion of ovarian reserves and consequent infertility, immunological factors, ovulation disruptions and light to moderate forms of male infertility.
Some 25 to 35 per cent of women subjected to IVF become pregnant; more precisely, the probability of success varies between zero and 70 per cent, depending on factors such as female age, the reasons for infertility and the experience of the IVF team.
In vitro fertilisation involves these steps:
The initial visit:
The physician draws up an IVF treatment plan and patients sign informed consent forms. An examination determines uterus size, shape and orientation using a catheter. This helps the treating physician decide where to place the embryos on the day of transfer. Prior to commencing the IVF cycle, the partner has to yield seminal fluid for analysis. Where donor sperm is to be used, this is the stage when a donor is selected.
The physician discusses suitable stimulation protocols with patients and prescribes medicines for ovarian stimulation. The process of stimulation is being monitored by the treating physician using ultrasonic examinations and blood tests to survey the hormone levels. Patients are usually prescribed medicines known as gonadotropin releasing hormone agonists (such as Decapeptyl) or gonadotropin releasing hormone antagonists (such as Orgalutran or Centrotide). These medicines prevent the early maturing and ovulation of egg cells during IVF stimulation.
Prescriptions follow for medicines known as gonadotropins (such as Puregon, Gonal-F and Menogon) which stimulate the ovaries to produce more egg cells. Gonadotropins are applied as injections in the abdomen, upper arm or thigh. The treating physician determines the appropriate dose for the patient and advises her of risks, possible side effects and the benefits of these medicines.
Egg cell aspiration:
Follicular puncture is conducted under anaesthesia and usually lasts around half an hour. Egg cell aspiration uses a transvaginal ultrasound device with a special probe with a long thin needle. The egg cells taken are placed into an incubator which maintains the right temperature and conditions for fertilisation and later embryo development. After the follicular puncture, patients spend around two hours in a recovery room. The manipulation is an outpatient one: no hospital stay is needed.
Egg cell insemination and fertilisation:
On the day of follicular puncture, the partner releases seminal fluid which will fertilise the egg cells. Three to five days of prior sexual abstinence is recommended. The seminal fluid is subjected to special processing and some four to six hours after egg cells are aspirated, they are inseminated. On the following day, egg cells are assessed for fertilisation, whose characteristic feature is the presence of two pronuclei. One of them contains the genetic material of the egg cell, while the other contains that of the spermatozoid.
|A mature egg cell||A fertilised egg cell at the pronuclei stage|
Embryo development and transfer:
With a view to selection, fertilised egg cells – now termed embryos – are cultivated for no less than 48 hours prior to transfer into the patient’s uterus. Embryo transfer may take place on the second, third, fifth or sixth days. The treating physician and embryologist discuss embryo quality with patients and jointly decide how many embryos to transfer into the uterus. Usually, one to three embryos are transferred, depending on quality, the reason for infertility and patient age. The procedure is painless and does not require anaesthesia. Patients in our clinic may observe the embryos and their transfer through a catheter on special monitors.
|A two cell embryo||A four cell embryo||An eight cell embryo|
The treating physician will set an appointment for pregnancy testing some two weeks after the follicular puncture and embryo transfer.