There's good news for moms who used infertility treatments: A new study shows no link between fertility treatments like IVF and delays in child development.
For parents who used infertility treatments to become pregnant, the lingering question of whether there could be any long-term effects on their children often remains. Because IVF (in vitro fertilization) and other technologies are fairly new, not much research has been done yet to see whether the treatments could lead to problems later on. But a new study published in the journal JAMA Pediatrics should give reassurance: Children conceived with infertility treatments are no more likely to have developmental delays that those conceived without.
No difference in development
Researchers looked at more than 1,800 children born after infertility treatments and compared them to more than 4,000 children whose moms didn't undergo treatment, all from upstate New York. "Mothers joined the study after delivery and answered surveys about their children's health every four to six months until their child was about three years old," Edwina Yeung, Ph.D., an investigator at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), tells Fit Pregnancy. "Based on these surveys, we found that children conceived by infertility treatment developed similarly as children not conceived by treatment, when we accounted for twinning."
Specifically, Yeung and her colleagues analyzed the kids' results in five categories: fine motor skills, gross motor skills, communication, personal and social functioning, and problem solving ability. "Included in the surveys were questions about how their children were doing in terms of their development—for example walking down stairs, drawing things, speaking, copying certain activities, figuring out how to do things," Yeung says. These types of broad-stroke guidelines help doctors see if kids are progressing along a normal path, or if they might be at risk for various conditions ranging from speech delays and learning disabilities to cerebral palsy and autism spectrum disorder. In this study, the researchers also found no difference in the percentage of children in each group who were referred for evaluation by developmental specialists, or who were diagnosed with a disability by three years old.
The twin factor
There is one catch to the study, though: The researchers had to adjust for the fact that there are more twins born to women who used infertility treatments. Taken as a whole, the treatments group was more likely to have delays; but when comparing only single-born babies, they were not more likely to have delays. "One reason is because twins are more likely to be born much earlier than singletons, and being born earlier increases risk for developmental delays," Yeung says.
In fact, the greater number of twins may be part of the reason why some studies have shown increased risks for children born from infertility treatments. "Concerns came because studies have shown that babies conceived by infertility treatment were born smaller and earlier, both of which can increase risk for developmental delays," Yeung says. "A few previous studies found differences in development but most have not." However, she notes, most other studies were done outside of the U.S., where standards and practices for infertility treatments might not be the same.
But besides the greater instance of twins, why would infertility treatments cause problems in babies? "There has been long-standing interest in the health of children conceived by infertility treatments," Yeung says. In IVF, the egg is fertilized in a lab before the resulting embryo is placed back inside the woman's uterus—and it's not clear if all that handling could have an effect on the delicate cells. It's also possible that the underlying causes of infertility itself could have an impact. For her purpose, though, Yeung was only concerned with the children after they'd been born. "We cannot comment on embryos since we asked survey questions starting after delivery and did not have data on embryo conditions," she says.
Yeung admits her study has some limits—she only looked at children in one state, and not all delays may be present at three years of age. So, more research is needed. "We are also continuing to follow the children about other aspects of health that are important to look into when they are older," like attention span and metabolism, she says. But overall, her results are positive for parents who used infertility treatments, especially given the lack of conclusive past research. "This finding is reassuring," Yeung says.