Pregnancy and Oncology - 4 Questions for an Obstetrician-Gynecologist

In the USA, many cancer patients are offered to freeze germ cells before starting treatment to give birth to healthy children in the future. In Israel, this is almost a mandatory procedure. This article will talk about pregnancy and oncology with special attention to the following aspects.

• Chemotherapy and germ cells
• Cryopreservation of germ cells
• Joint management of the patient by an oncologist and a reproductive specialist
• Shelf life of germ cells in cryostorage

Oncology and Pregnancy

You say, what kind of cancer patients think about the offspring and pregnancy?! They care about one thing - survival. But many malignant diseases are successfully treated. For example, breast cancer and melanoma, detected at stage 1, are cured in 90% of cases, as most other cancer types noticed in time. And when patients recover, many of them think about children. But they can expect a new test - infertility. Is there a chance for people who have beaten cancer to become parents?

There is a belief that "chemistry" damages germ cells. Because of this, people cannot conceive a child. Is it true?

You're right. Oncologists are now trying to do organ-preserving operations. For example, earlier, the diagnosis of "cervical cancer" was a sentence for nulliparous women: the uterus was removed, and with it, the hope of having a child disappeared. Today, they try to save the organ (although everything depends on the stage). The same applies to ovarian cancer - if possible, one ovary is left. But surgeons cannot guarantee that they have removed all diseased tissue. Therefore, chemotherapy is prescribed - it destroys those malignant cells that could remain in the body. It is indispensable in many cases. However, along with diseased cells, healthy ones are also damaged, including germ cells.

In men, spermatogenesis is often inhibited after chemotherapy. And in women, the ovarian reserve (egg reserve) decreases. In addition to the fact that it declines every year - by the age of 38, women have much fewer chances to get pregnant naturally without egg donors. But chemotherapy drugs reduce the egg reserve even more. Naturally, the chances of conception are greatly reduced.

How can reproductive specialists help cancer patients?

Reproductologists can save germ cells until the patient recovers. And then use the biomaterial for conception with the help of assisted reproductive technologies. Some clinics even offer free freezing of germ cells for cancer patients.

If the "chemo" is for a woman, doctors can freeze a piece of ovarian tissue and then transplant the tissue back. They can also preserve eggs, both mature and immature. Earlier, it was extremely difficult to maintain and save oocytes - female germ cells. The size of an egg is 150 microns; it is the largest cell in the body. For comparison: the size of a spermatozoon is only 2 microns. With simple cryofreezing, oocytes are cooled unevenly, which leads to their destruction. Now the method of ultra-fast cryopreservation is used - vitrification, which practically excludes the destruction of germ cells. In this case, crystalline ice is not formed inside the egg (namely, ice cannot damage the cell's structure). Vitrification of embryos is also possible. Even if doctors save one embryo, this is a real chance of pregnancy.

If a man is given chemotherapy, he can freeze his sperm. And when he decides to become a father, we will unfreeze the spermatozoa, evaluate their quality and choose the best ones.

Cancer patients should consult fertility experts before starting a course of chemotherapy to avoid damaging effects on tissues. However, it is possible to obtain suitable reproductive material in some patients after specific oncological treatment.

Is an oncologist's opinion necessary before doing any manipulations with germ cells?

It is highly necessary! There must be an extract from the oncology dispensary. In addition, gynecologists and reproductologists should constantly contact the oncologist. They need to understand what stage of cancer a person has, which reproductive methods are suitable, and which are not. For example, can a woman be stimulated with hormones? And in general - is it possible for her to get pregnant?

In most cases, pregnancy has a beneficial effect on the female body - the risk of developing breast cancer, endometrial cancer, and ovarian cancer is reduced. But if a woman has hormone-dependent cancer, you need to think twice. Here the decisive word belongs to the oncologist. After all, during pregnancy, the level of hormones greatly increases. The amount of estradiol can increase tenfold. And it would be best if you weighed all the possible risks.

And if a woman has ovarian cancer, before carrying out the conservation of ovarian tissue, it is necessary to carefully examine the sample so that there are no pathological cells. In short, the approach must be serious.

A cancer patient does not know when one will recover. One can come for the cells in 10-15 years. What if they get spoiled?

Of course, a cryobank is not a safe deposit box: put it and forget it. It is a living system that requires constant monitoring. Trusted clinics have autonomous power plants - so that in the event of a power outage, the cryo-storage and the operating incubators are not affected. And modern methods of cryopreservation will not allow cells to "spoil." They practically exclude damage to the biomaterial.