Babies conceived via IVF are born smaller than others… but catch up on height and weight by the age of 17, research shows
- By age of 17, IVF children were same average size as those conceived naturally
- Babies were initially smaller but research found a difference in growth patterns
- Previous research linked rapid weight to higher blood pressure and diabetes
Children conceived through IVF are born smaller but then grow more quickly, researchers have found.
By the age of 17, there are no differences in the average height or weight of IVF children compared with those who were conceived naturally, the scientists said.
Previous research has found that fertility treatment produces smaller babies. But this is the first study to show that IVF children quickly catch up.
By the age of 17, there are no differences in the average height or weight of IVF children compared with those who were conceived naturally. Picture: Stock
The research, which followed 80,000 children until they were seven, found IVF babies are actually taller and heavier at the age of one.
This speedier growth rate for IVF children persists until the age of seven, according to the study published in Human Reproduction.
Lead author Dr Maria Magnus said: ‘Our study is the first to show clear differences in the growth patterns between children conceived after fresh and frozen embryo transfer up to school age.’
The team from the Norwegian Institute of Public Health also looked at data from 544,113 teenagers. This included information on conception, as well as self-reported height, weight and BMI at the age of 17.
There was little difference between the height or weight of naturally conceived teenagers and those born after IVF treatment.
Dr Magnus said this was reassuring. She said further study is now needed to assess the effects of faster growth on later health.
The research, which followed 80,000 children until they were seven, found IVF babies are actually taller and heavier at the age of one. Picture: Stock
Previous research has linked the rapid weight gain in IVF children to higher blood pressure and type 1 diabetes.
The Norwegian researchers said the IVF children they assessed had an average birthweight of 7lb 11oz (3.5kg) and an average height of 19.7in (50cm). This was smaller than the 7lb 15oz (3.6kg) and 19.8in (50.3cm) in naturally conceived babies in the study.
Children conceived through IVF may be smaller at birth because of the hormone treatment used to stimulate ovulation in mothers, which could change the way babies’ cells behave.
About 20,000 IVF babies are born in Britain each year, equivalent to 2 per cent of births.