In vitro fertilisation (IVF)
If the woman’s Fallopian tubes are irreparably damaged, if she suffers from severe endometriosis or if less sophisticated methods of treating infertility caused by immunological, andrological, or unknown factors have failed, in vitro fertilisation (i.e. fertilisation outside the body) is often the only promising way of achieving a pregnancy.
In this case, the woman is given hormone injections (gonadotrophins) to stimulate the growth of several oocytes (egg cells) in both ovaries. The tolerability of the hormones and the reaction of the ovaries to them varies from patient to patient. Every stimulation is therefore monitored by ultrasound and hormone controls.The injections are normally administered over 9-14 days, and 2-4 ultrasound and blood tests are carried out in this period.
If the tests suggest that some mature oocytes are present, ovulation is triggered by drugs, and around 36 hours later – when ovulation is about to occur – the oocytes are retrieved in our clinic by ultrasound-controlled aspiration through the vagina with the patient under conscious sedation.
On the day of oocyte retrieval, we also need a sperm sample from the male partner. Both egg and sperm cells are then together introduced into a special culture medium in our IVF lab and transferred into an incubator for fertilisation.
The embryo is transferred to the patient 2-3 days after oocyte aspiration (5-6 days in the case of blastocyst culture). The early embryos (mostly in the 2-8-cell stage or blastocytes) are transferred into the uterine cavity using a soft plastic catheter under ultrasound control. No anaesthesia is required for the embryo transfer.
After the embryo transfer, most women are given progesterone (as vaginal tablets or gels) and sometimes some other medication in order to create ideal conditions for the implantation of the embryos.
Two weeks after the embryo transfer, we measure the pregnancy hormone HCG in the blood to see whether the treatment was successful.
According to the German Embryo Protection Act, we are allowed to transfer up to 3 embryos into the woman’s uterine cavity. Especially in women under the age of 35, however, we tend to transfer only 2 early embryos in order to keep the risk of multiple pregnancy as low as possible.
The average chance of achieving a pregnancy is around 33% per embryo transfer (20% will be twins and < 1% triplets, 20% miscarriages and 1-5% tubal pregnancies).
The so-called “baby-take-home rate” is 25% per cycle, but it can vary extremely between couples and depends a lot on the woman’s age, the number of previous failed attempts and many other factors. If either or both partners smoke, the chances of pregnancy are reduced by up to 50% compared with non-smoking couples!