• Posted July 16, 2024

Safe Pregnancies Possible After Stem Cell Treatment for Blood Cancer

Women who've undergone stem cell treatments for blood cancers, or for illnesses such as sickle cell disease, can successfully bring a pregnancy to term, new research shows.

The German findings run counter to the perceived wisdom on this issue: Many such patients are typically told that safe pregnancies are out of the question if they've undergone what's known as "allogeneic hematopoietic cell transplantation" (alloHCT).

However, "the results of this study show that female alloHCT recipients can achieve successful and safe pregnancies,"concluded study author Dr. Katja Sockel. She's a senior physician at University Hospital Carl Gustav Carus Dresden, in Germany.

The study, which is the largest to date in adult female alloHCT recipients, was published July 15 in the journal Blood.

As the researchers explained, an alloHCT involves taking stem cells from a healthy donor and implanting them into a patient who has conditions such as blood cancers or sickle cell disease.

But these transplants come with risks, including long-term use of immune-suppressing medications and the prior use (in cancer patients) of radiation or high-dose chemotherapies. These can all threaten a woman's fertility.

"Fertility is a very important topic for young female patients," Sockel explained in a journal news release. "Some patients even opt out of receiving certain treatments because of concerns about fertility. For young adult cancer survivors especially, the return to a normal life includes family planning."  

So, could pregnancy really be out of reach for these patients?

To find out, Sockel's looked at data from the German Registry for Stem Cell Transplantation. They calculated pregnancy and birth rates, as well as numerous risk factors, for 2,654 female patients who'd undergone alloHCT between the ages of 18 and 40.

Of that group, "50 women reported 74 pregnancies, 57 of which resulted in live births, with a median time from [stem cell] transplantation to first pregnancy of 4.7 years," according to the journal news release.

Pregnancy was more likely if the woman was between the ages of 18 and 35 at the time of her stem cell transplant, and pregnancies occurred at an average age of just under 30.

Pregnancy rates were still low, about six times lower than that of German women without such medical histories, the team noted.

Still, healthy pregnancies did occur. In most cases (72%), these pregnancies occurred without the use of fertility treatments, Sockel's team noted.

"Some study participants reported that they had not taken measures to prevent pregnancy because their doctor told them conception was not possible,"Sockel explained.

"Spontaneous pregnancies should not be underestimated, and female patients should be educated about potential fertility restoration post-alloHCT, to prevent unplanned or unwanted pregnancies," she said.

Certain factors did seem to affect the odds for a pregnancy, the researchers noted.

These included less intense "conditioning regimens;" receiving the stem cell transplant for a nonmalignant condition; and reducing the radiation dose in total body radiation therapies.

There were sometimes complications linked to pregnancies among women who received stem cell transplants -- most notably vascular issues such as preeclampsia, edema (swelling) and hypertension.

Still, the rate of these complications did not exceed those found in the general population, the researchers said.

Nevertheless, close monitoring by transplant physicians and gynecologists is recommended during any pregnancy involving these types of patients, the team added.

As for the health of babies, the study did find heightened odds for premature delivery and low birth weight, according to the researchers.

More information

Find out more about alloHCT at the Leukemia & Lymphoma Society

SOURCE: American Society of Hematology, news release, July 15, 2024