Babies born from frozen embryos are more likely to develop cancer

Babies born from frozen embryos may be more likely to develop cancer, according to a study of nearly 8 million Scandinavian children.

The researchers said the risk was still very small, but urged clinics that freeze embryos for “convenience” to reconsider their practice.

The team compared the health records of 7,944,248 children born between 1984 and 2015 in Denmark, Sweden, Norway and Finland.

More than 170,000 of these children were born with the help of assisted reproductive technology (ART), of whom some 22,630 were born after frozen embryo transfer.

ART includes processes such as in vitro fertilization (IVF) where the egg and sperm are joined in the laboratory instead of in the womb. The resulting embryo is transferred to the woman’s uterus where it grows and develops as a natural pregnancy.

In some cases, the embryos are frozen and thawed before being implanted in the uterus. This can occur for various medical or other reasons.

The researchers compared information on how each baby was conceived in a large registry with information on childhood cancers.

People born after frozen embryo transfer are 1.6 to 1.7 times more likely to develop cancer than those born after fresh transfer or without fertility treatment.

The number of children who developed cancer was still very low in each group, with 2 out of 1,000 developing cancer in the cryotransplantation cohort. Other children are affected in less than 1.5 per 1,000.

Christina Berg, a professor of obstetrics and gynecology at the University of Gothenburg and a co-author of the study, told Euronews Next that the results shouldn’t surprise parents.

“Actually, this growth is quite modest. And this is very reassuring for parents. Most of the children are healthy.

But given the growing popularity of frozen embryo transfers, the team says it’s important to understand the potential consequences of the process.

For example, some clinics may freeze embryos for convenience, such as allowing transfers outside of weekends and holidays.

“Our message is that you have to freeze it [embryos] It’s for medical reasons, not for other reasons,” Berg said.

“Our study shows that there appears to be a higher risk of cancer in frozen babies than in fresh embryo transfer newborns. And more care needs to be taken with all freezing approaches.”

This study, published in PLoS One, is not without limitations. Although many variables were taken into account, including embryonic stage, maternal age, and birth order, this study could not prove that freezing embryos causes cancer.

Because this is an observational study, even in such a large cohort, the researchers can’t rule out many factors, such as genetics and lifestyle, that could influence the results.