IVF children with birth defects at greater cancer risk: JAMA
USA: Children conceived through in vitro fertilization (IVF) having birth defects are at a greater risk of cancer compared children conceived naturally, suggests a recent study in the journal JAMA Network Open.
Children having birth defects have a greater risk of developing cancer. However, this association has not yet been evaluated in children conceived via IVF. Barbara Luke, College of Human Medicine, Michigan State University, East Lansing, and colleagues assessed whether the association between birth defects and cancer is greater in children conceived via IVF compared with children conceived naturally.
For the purpose, the researchers conducted a cohort study of birth defects, cancer, and live births from North Carolina, Texas, Massachusetts, and New York. It included 1 000 639 children born to fertile women and 52 776 children conceived via IVF. Children were followed up for an average of 5.7 years (6 008 985 total person-years of exposure). Data analysis was conducted from April 1 to August 31, 2020.
All births were grouped into categories of fertile and IVF. Children were stratified according to the number of birth defects they had. A total of 1 000 639 children (51.3% boys; 69.7% White; and 38.3% born between 2009-2012) were in the fertile group and 52 776 were in the IVF group (51.3% boys; 81.3% White; and 39.6% born between 2009-2012).
Those having gestational age of less than 22 weeks or birth weight of less than 300 g were excluded. In the IVF cohort, only births conceived with autologous oocytes and fresh embryos were included, as those conditions most closely paralleled natural conception.
The primary outcome was cancer diagnosis as recorded by state cancer registries.
Key findings of the study include:
- Compared with children without birth defects, cancer risks were higher among children with a major birth defect in the fertile group (hazard ratio [HR], 3.15) and IVF group (HR, 6.90).
- The HR of cancer among children with a major nonchromosomal defect was 2.07 among children in the fertile group and 4.04 among children in the IVF group.
- The HR of cancer among children with a chromosomal defect was 15.45 in the fertile group and 38.91in the IVF group.
"Our results showed that cancer risk increased in the presence of birth defects at a higher rate in children conceived via in vitro fertilization than in children conceived naturally; further study is warranted," concluded the authors.
The study, "Assessment of Birth Defects and Cancer Risk in Children Conceived via In Vitro Fertilization in the US," is published in the journal JAMA Network Open.