Being born small doesn’t tend to hinder IVF babies’ cognitive development

New research using CNC has found that children conceived through fertility treatments, including IVF (in vitro fertilisation) who are born small do just as well in cognitive assessments throughout childhood and adolescence (such as reading and vocabulary tasks) as naturally conceived children who are born a normal weight.

What we asked you and your parents

When you were born, we asked your parents whether they had used fertility treatments like IVF or artificial insemination to conceive. We also asked them some questions about your family background, including your mother’s educational level, age at birth and marital status.

When you were 3, 5, 7, 11 and 14, we asked you to complete various cognitive assessments, including naming a word from a picture at age 3, identifying picture similarities at age 5, reading a series of words at age 5, and vocabulary tasks at ages 11 and 14.

What the researchers found

Children conceived with the help of fertility treatments who were born small did just as well or better in these tasks as naturally conceived children who were born a normal weight. In addition, children conceived through fertility treatments who were born a normal weight actually tended to do better than their naturally conceived counterparts (whether born small or normal weight).

Although children born through fertility treatments were much more likely to be born small than naturally conceived children, they were also more likely to have parents who were well off and well educated. The study’s authors explained that having access to greater financial and educational resources, especially in early childhood when parental involvement in learning is key, may compensate for the possible initial disadvantage being born small.

Why this research matters

Over 20% of children conceived through fertility treatment are born small. While previous research had shown that children conceived through fertility treatment tended to perform as well as or better in cognitive tests than naturally conceived children, these studies had not looked at whether this is the case for those born small. This study will provide reassurance to parents considering fertility treatments by showing that being born small does not tend to hamper the development of children conceived this way.

Find out more about this research

The full scientific paper was published in the International Journal of Epidemiology in March 2021.

These findings were featured in The Telegraph (£).