Detailed inform­a­tion and a list of ref­er­ences can be found in Chapter 3.1 of the FertiPROTEKT book, “Indic­a­tions and fertility pre­ser­va­tion methods for onco­lo­gic­al and non-onco­lo­gic­al disorders”, which can be down­loaded free of charge.


The aim of egg cell mat­ur­a­tion treatment (stim­u­la­tion) is to produce mature egg cells (oocytes) that can be frozen either fer­til­ized unfer­til­ized. This method should be performed as quickly as possible as part of the necessary treatment of the under­ly­ing disease. Often, only one attempt is possible in the time available, and this should proceed as optimally as possible to collect the maximum number of mature egg cells without increased risks.

It is important that embryos can only be trans­ferred later with the consent of the partner. However, since the cells may be stored for several years it must be con­sidered that if the couple are no longer in a rela­tion­ship, then the fer­til­ized egg cells cannot be trans­ferred. To avoid this risk, “splitting” is advised (50% of egg cells frozen fer­til­ized, 50% frozen unfer­til­ized), even for patients in a stable rela­tion­ship, to ensure the woman’s independence.

Stim­u­la­tion treatment started at the time of men­stru­ation is a routine procedure.


The number of oocytes collected depends on the age and the ovarian reserve of the woman and must be assessed indi­vidu­ally by the physician. The average number of egg cells is according to the FertiPROTEKT register is ca.12 in women who are younger than 36 and 8 at 36–40 years of age. The freezing of unfer­til­ized egg cells has only slightly lower fer­til­iz­a­tion rates and pregnancy rates than freezing of fer­til­ized ova.


The costs of egg cell col­lec­tion are slightly different depending on the centre and are broken down approx­im­ately as follows:

  • drug costs (depending on the required dose and duration of treatment): 1500 to 2000Euros
  • stim­u­la­tion method (ultra­sound mon­it­or­ing, oocyte retrieval): 1000 to 1500 Euros
  • freezing and storage for 1 year: 400 to 800Euros

If the couple are married, a health insurance applic­a­tion can be issued (in Germany) at short notice, so that the costs are entirely or partially (depending on the insurance status) covered.



To make oocyte col­lec­tion possible, oocyte mat­ur­a­tion must be stim­u­lated by hormones. Injec­tions are used for this which patients can admin­is­ter them­selves for 10–12 days, after tuition. To prevent undesir­able premature ovulation, a second injection is added during the course of treatment, so that 2 injec­tions are admin­istered every day for about 5 days. The dose is adjusted where necessary according to regular ultra­sound exam­in­a­tions, which are usually performed 2–3 times (every 2–3 days).


The situation in women with hormone receptor positive tumours, e.g. hormone receptor positive breast cancer, is a special situation because hormone pro­duc­tion is stim­u­lated during oocyte mat­ur­a­tion, which could the­or­et­ic­ally con­trib­ute to tumour growth. To reduce the increase in estrogen levels during treatment, the addition of special drugs which inhibit estrogen pro­duc­tion is recom­men­ded. Since these so-called “aromatase inhib­it­ors” are not approved for ovarian stim­u­la­tion and the treatment is “off-label” (i.e. pre­scrip­tion at cost price). Previous studies have not demon­strated any increased mal­form­a­tion rates in children who were conceived using this method.


In treat­ments where there is a high prob­ab­il­ity of the ovarian function being damaged, oocyte col­lec­tion can be combined with the removal of ovarian tissue. Half an ovary should be removed during lap­aro­scopy and oocyte stim­u­la­tion can be started two days later. The data on such a com­bin­a­tion of tech­niques has not shown any increase in com­plic­a­tions. The number of collected oocytes does not appear to be reduced. The time required for the combined procedure is about 2.5 weeks.