Background: There is limited information regarding the long-term outcome of children born following in vitro fertilization (IVF) although an increase in rare imprinted gene disorders such as Beckwith Wiedemann Syndrome has been reported.

Methods: We recruited healthy, pre-pubertal children born at term following singleton pregnancy. The study group were conceived using IVF with fresh embryo transfer whilst controls were naturally conceived. Anthropometric measurements, bone age, dual energy X-ray absorptiometry fasting serum glucose, insulin, lipid profile, insulin-like growth factors (IGF) -I and -II and insulin-like growth factor binding protein (IGFBP) 1, 2 and 3 were performed.

Results: There were 69 IVF children aged 5.9±0.2 yrs and 71 control children aged 6.9 years. IVF children were taller than controls when corrected for parents' heights (height standard deviation score 1.05±0.1 versus 0.51±0.11, p=0.001) with higher levels of serum IGF-II (850±24 versus 773±24 ug/l, p=0.03), higher IGF I: IGFBP3 ratio (p=0.04) and a trend toward higher IGF-I (105±4 versus 92±4 ug/l, p=0.06). IVF children had higher high density lipoprotein (1.67±0.04 mmol/l vesus 1.53±0.04 mmol/l, p=0.02) lower triglycerides (0.65±0.04 mmol/l versus 0.78±0.04 mmol/l, p=0.02) and a lower total: high density lipoprotein cholesterol ratio (2.58 versus 2.86, p=0.01). There were no differences in body composition.

Conclusions: IVF children are taller with higher IGF I and IGF II levels and have a slightly more favourable lipid profile. We speculate that IVF results in epigenetic change through altered methylation of genes involved in growth and metabolism. IVF programs should consider long term longitudinal follow up of IVF offspring.