No increased cancer risk in ART-conceived children

The risk of cancer is not elevated in children and young adults who were conceived after assisted reproductive technology (ART), including in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and fresh or frozen embryo transfer, compared with those conceived naturally, according to a study presented at ESHRE 2021.

Using data from the OMEGA cohort, the researchers prospectively analysed 51,417 children who were born after ART (ART group; median attained age 16.4 years) and 37,832 children who were conceived naturally (non-ART group; median attained age 20.3 years) by subfertile women treated at 13 IVF clinics and two regional fertility centres in The Netherlands. The incidence of cancer was ascertained through the Netherlands Cancer Registry. [ESHRE 2021, abstract O-077]

Overall, 157 and 201 cancer events occurred in the ART and non-ART group, respectively.

At a median follow-up of 17 years, children conceived after ART showed no overall increased risk of cancer compared with those who were conceived naturally (hazard ratio [HR], 1.06) or the general population (standardized incidence rate, 0.96).

The risk of cancer was also not increased when the children were stratified by attained age (HR, 0.94, 1.24, and 1.04 for age <10, 10–19, and ≥20 years, respectively).

IVF-conceived children had no increased risk of cancer vs non-ART-conceived children (HR, 0.97). However, in children conceived by ICSI, the risk of developing cancer was higher than those who were conceived naturally (HR, 1.58).

Lead author Dr Mandy Spaan from the Department of Epidemiology at Netherlands Cancer Institute, Amsterdam, The Netherlands, primarily attributed this result to an increased risk of melanoma following ICSI despite having only four cases of melanoma reported.

The risk of cancer was also slightly higher in children born after frozen vs fresh embryo transfer (HR, 1.56), but this was not statistically significant.

“[Overall,] the results are very reassuring,” said Spaan. Despite the increased cancer risk tied to IVF or ICSI treatments, these only apply to certain cancers and at lower incidences, such as the melanoma cases tied to ICSI in this study, she added. “[As such, this] could either be a true finding or a chance finding … A longer follow-up is needed before definitive conclusions can be drawn,” she concluded.