In vitro fertilization

In vitro fertilization (IVF) was originally developed as a treatment method used when there is a fault with the fallopian tubes. Nowadays, IVF is the most efficient treatment method regardless of the causes of infertility. With each couple in question, this treatment also allows us to obtain new information on the background of their infertility.

The IVF cycle is started with hormonal treatment, with the objective of maturing several follicles simultaneously in the ovaries. Thus, several eggs can be retrieved, of which 2/3 are fertilized and begin to multiply. There are many factors, however, affecting the number of eggs and their fertilization. The treatment is carried out by maturing the follicles for about 10 days with hormonal injections. The response to these injections is followed by ultrasound scans. After this, ovum pick-up is performed using transvaginal ultrasound.

The retrieved ova are fertilized on culture dishes by adding a sufficient number of sperm. The fertilized eggs are normally cultured for 48 hours. By this stage, the fertilized oocytes will have been divided into the 2-4-cell stage. One or two of the best embryos are selected for the transfer, and if there are several good-quality embryos, the rest can be frozen for later use. Embryo transfer is a procedure where the embryos are introduced into the uterine cavity with a soft thin plastic catheter.

4-cell stage ebryo	8-cell stage ebryo

Risks and side-effects

There are two clear risks involved with in vitro fertilization. Firstly, women react very differently to the hormonal treatment. For the majority, it is possible to determine the appropriate hormonal dosage according to age and body weight, the appearance of the ovaries in the ultrasound scan, and according to possible previous treatment.

Some of the patients react badly to hormonal treatment and it is possible that the dosages have to be increased accordingly. A small number of patients, however, react very strongly to the administered treatment. In these cases, the ovaries may develop 30-40 follicles, the ovaries consequently become large and swollen and there may be an accumulation of fluid in the abdomen, which causes pain and nausea. This condition is called the ovarian hyperstimulation syndrome (OHSS). Often rest and ensuring adequate fluid intake are sufficient treatment, but in the worst cases hospitalization may be required.

A second risk involved with IVF treatment is the increased risk of multiple pregnancies. 1% of all naturally conceived pregnancies are multiple pregnancies whereas the corresponding figure for all IVF-induced pregnancies is 20-30%. Although the majority of multiple pregnancies are carried to term without difficulties, there is always an increased risk of premature birth, low birth weight and complications at birth. A good way to minimise these risks is to transfer only one embryo at a time into the uterine cavity.