The association of rapid weight gain on health is time critical in those born preterm; in early infancy, this does not impact on metabolic status in adolescence, in contrast to rapid weight gain in childhood, which should be discouraged. However, given the critical importance of brain growth in the neonatal period and infancy, further research is needed before strategies that discourage infant weight gain or catch-up can be recommended for infants born preterm.

No infant with a normal TSH concentration on first sampling had a TSH concentration that rose above 10 mU/l on second sampling, and no infants with a normal TSH concentration on first screening are receiving long-term thyroxine treatment. This study suggests that a second sample may not be necessary with a screening threshold of 6 mU/l.

In a monochorionic twin cohort, fetal growth restriction results in lower neurocognitive scores in early childhood, and there remain significant differences in size. Longer term follow-up will be required to determine whether growth or cognitive differences persist in later child or adulthood, and whether there are any associated longer term metabolic sequelae.