The chemotherapy used for BMT can cause temporary or permanent infertility. Infertility is the inability to have children. This is an important consideration for parents who are considering a BMT for their child and for those making the decision for themselves.
In general the doctors and nurses involved in your care will discuss fertility issues and the options available for preserving eggs and sperm in the planned lead in period to BMT. In some cases, however, this may not be possible because of the need to start BMT urgently when a patient is seriously ill.
This section deals with this sensitive issue in the non-urgent setting and looks at the different issues for males and females and how they may influence the decision to have a BMT and its timing.
Options to preserve fertility pre-BMT
For male patients
For older boys it is possible to preserve fertility before BMT by having the sperm frozen and banked for future use in either artificial insemination or in vitro fertilisation. Sperm banking involves the patient giving sperm samples and freezing and storing them in liquid nitrogen. The sperm samples will be checked to see if they are viable for storage checking for how many sperm there are, their motility (the ability to move), and normal cell shape, before freezing and after thawing.
Your BMT team will discuss your options about sperm collection and banking with you.
However for young boys sperm banking may not be possible because of the inability to produce enough viable sperm. In this case, and only if your doctors recommend it is safe to do so, BMT can be delayed until a time when viable sperm can be collected.
For female patients
As we all know girls are different from boys! Girls are born with a fixed number of eggs made by the ovaries in contrast to males who continue to produce new sperm throughout their life. For females this makes the effect of chemotherapy on future fertility more complicated, as the effect on immature eggs in the ovum is unknown. In addition, it is more difficult to preserve ovarian tissue or eggs because these are much more fragile than sperm.
The impact of chemotherapy on future fertility has implications for considering BMT for females affected by the autosomal recessive type of CGD. This may be one the factors to take into consideration for girls (and boys) with autosomal recessive CGD, although there are many other important considerations presently girls with autosomal recessive CGD will not generally not have a BMT unless clinically urgent due to the question of future fertility but this can be down to individual choice. The people involved in your care will discuss the options that might be available to you.
Options available to preserve fertility pre-BMT include:
Freezing your eggs. Mature eggs are stimulated, removed, and frozen unfertilised. This method can require several weeks to accomplish, and depends on the individual’s menstrual cycle. These eggs would then be used for in vitro fertilisation (IVF) in the future.
Ovarian tissue freezing. Ovarian tissue is removed during an outpatient surgical procedure and frozen for future transplantation back into your body. This method is considered experimental. Its aim is to preserve immature eggs and the tissue that makes female hormones to potentially preserve female fertility.
Medicines. Medicines, such as Lupron— which is a hormone — might be offered during treatment to prevent the cells of the ovary from growing, potentially making them less susceptible to the effects of chemotherapy. This method is also experimental.
Fertility post BMT
There is little research about fertility after bone marrow transplant (especially for rare conditions like CGD) and it is difficult to predict if or when fertility will return. Some people who have had chemotherapy for cancer and other conditions have gone on to have children naturally post BMT but this is rare. Furthermore, many of the drugs we use now are different or used in different doses or combinations to years ago, so their true effects on fertility are not known as not enough time has passed for the children to have become adults and start thinking about having their own children.
For those people who have already had a BMT and were unable to store sperm or eggs there are options available so they can have a family.
For women these include in vitro fertilisation with donor eggs or adopted embryos or adoption.
For men using a sperm donor is one option. Another is a new technique called testicular sperm extraction. It is suitable for those who did not have mature sperm present in their semen, before or after BMT and makes use of the possibility that there may still be sperm in testicular tissue that can be used with in vitro fertilisation (IVF) to try to achieve pregnancy.
Testicular sperm extraction is an outpatient surgical procedure available for males after puberty. Testicular tissue is obtained by biopsy and then examined for sperm cells. If sperm cells are found, they are removed and used immediately or frozen for future use with in vitro fertilization (IVF) and ICSI (Intracytoplasmic Sperm Injection) to achieve a pregnancy.
You should discuss this with doctors looking after you or your GP who will be able to give you more information or refer you to someone who can help.