Methods of treatment available include the following techniques, whose application in Bulgaria was pioneered by the Centre’s founder:
In vitro fertilization and embryo transfer (IVF-ET)
Fertilization in vitro literally means fertilization in glass (plastic) containers, i.e. fertilization outside the body – eggs are collected and placed together with a prepared and washed sample of sperm. Fertilization takes place in the special dish and embryos then grow on for two to five days, after which they are transferred to the female partner. The method is used to treat female (tubal damages), some forms of male infertility (slightly reduced sperm count or anti-sperm antibodies), unexplained and cases of mixed (male and female) infertility. The IVF treatment cycle include the following steps:
ovarianstimulation: the most commonly regime uses a drug to “switch off” (down regulate) the pituitary gland and after that ovarian stimulation may start with every day injections of different FSH preparations ;
monitoring of the developing ovarian follicles and endometrium: first scan is usually on day 5-8 after the start of stimulation and the dose of drugs is then adjusted if necessary ; when follicles have reached the size of 18-20 mm will be given an injection of HCG – this causes the final maturation of eggs in the ovarian follicles and determines the time of egg collection ;
egg collection: on the day of egg recovery the female partner will be prepared for surgical aspiration while the male partner will be asked to provide a semen sample. The puncture of the ovaries is carried out by the vaginal ultrasound technique usually under local anaesthesia or with a relaxing and painkilling injection only ;
fertilization outside the body: The eggs are collected and washed before being placed in the CO2 incubators. Depending upon the maturity of the eggs, after some hours, they are inseminated (some time additional maturation is needed) and cultured together with a portion of specially prepared sperm. They are inspected the following day to see the first signs of normal fertilization – the presence of two pronuclei. A fertilized egg (the zygote) then divide into a two, three, four or more cell embryo (embryo culture procedure) ;
embryo transfer: This procedure is done two to five (usually three) days after egg recovery. We recommend that only two to maximum three embryos (as exception), may be transferred after discussion with couples at the time. Praescriptions & instruction on any further drugs, supporting the endometrium or treatment will be given to the couples.
The chances of a couple conceiving after IVF-ET (or other ART) depend of many factors including the couple’s age, cause and duration of infertility, type of treatment, number of embryos transferred etc. In our hands the success rate for one IVF-ET procedure is around or slightly above 40 % “taken home babies” .
Intrauterine insemination with husband’s or partner’s in vitro treated sperm.
Intrauterine insemination (IUI) procedures usually involve mild ovarian stimulation and monitoring the process of follicle development and ovulation by ultrasound scanning. A semen sample from the male partner is prepared such that normal and active (most motile) sperm are separated into sterile culture medium. By means of a fine catheter, a small volume of this sperm suspension is placed into the uterine cavity near to the ovulation time. The technique is only used if one or both fallopian tubes are known to be open, and the partner’s sperm parameters are near the normal or subfertile range. The success rate for this procedure usually is around 10% per attempt.
Intrcytoplasmic sperm injection (ICSI) and others modifications of the method – surgical sperm retrieval by percutaneus epididimal sperm aspiration /PESA/ and testicular sperm extraction /TESE/
The intracytoplasmic sperm injection method is new option for treating severe male infertility. This technique involves microinjection of a single sperm into each egg via micromanipulators. It is used mainly for cases where very few functional sperm are available and for patients who require surgical sperm retrieval (SSR). Where no sperm is found in the ejaculate (obstructive azoospermia), SSR-micro operation is used to extract sperm from the epididimis – percutaneous epidididmal sperm aspiration “PESA” or directly from the testicles (nonobstructive azoospermia) – testicular sperm aspiration “TESA”. As sperm retrieved in this way are immature, and are incapable of fertilization, the ICSI technique is always required to help penetration of male germ cells into the eggs. In many cases the ICSI success rates are little below to success rates for the conventional IVF-ET techniques.
Polar bodies biopsy, assisted hatching and microaspiration of cytoplasmic fragments or cells (embryo biopsy) from preimplantation embryos.
The embryos are surrounded by protective, transparent coating, named ‘zona pellucida’. Before an embryo can implant it must escape (or hatch) from this outher “zona” – if the coating has become thick or tough, the hatching process may be impaired. Assisted hatching involves making an opening in the zona pellucida to enable the embryo to escape and implant. A number of studies showed a significant benefit of assisted hatching, particularly in older patients.
The polar bodies/ embryo biopsy and aspiration of cytoplasmic fragments is a new approach for investigate eggs and blastomeres or “cleaning” moderate to bad quality embryos, before transfer. The degree to which the methods improve the chance of pregnancy is difficult for exact measure, as the reasons for using this technique are not identical in each case.
General steps and methotds of human assisted reproduction are shown here: