Method: Demographic and social data were extracted from national registers for all individuals born between 1974 and 1976 in Denmark (n=208 656). Of these, 203 283 individuals were alive in 2006. We compared VPT individuals (gestational age <33wks, n=1422; 51.8% males, n=736) with individuals born at term (>36wks, n=192 223; 51.1% males, n=98 240), of whom 4.08% (n=58) of the VPT and 0.19% (n=373) of the term individuals had a diagnosis of cerebral palsy (CP).

Results: Overall results in the two groups were similar, but significant differences appeared. The VPT group had a lower educational level than the term group: 23.9% versus 16.3% had a basic education (corresponding to attendance at basic school for 9y or less; odds ratio [OR] =1.61, 95% confidence interval [CI] 1.42–1.82). Similarly, 31.9% versus 37.6% had a tertiary education (corresponding to different levels of professional education; OR=0.77, CI 0.69–0.86). Net income was 11% lower in the VPT group and 10.8% versus 5.3% were receiving welfare support (OR=2.14, CI 1.81–2.55). In the VPT group 59% versus 52% did not have children (p<0.001) and there were more individuals living alone without children (28.8% vs 21.8%; OR=1.45, CI 1.29–1.63).

Interpretation: VPT birth in the 1970s in Denmark is associated with a highly statistically significant educational and social disadvantage persisting into young adulthood. CP increased the relative risk of social disadvantage in VPT individuals. However, the majority of the survivors are well integrated in society.

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Comments: Neonatal intensive care as we know it today was "born" in the 1970s and has resulted in dramatic improvements in survival for infants born preterm.  Unfortunately, it is clear that these children are at much greater risk than their full term counterparts for neurosensory, motor, cognitive and behavioural disturbances.  Many families struggle with the challenges of raising a child or children affected by one or more of these disabilities and the uncertainty of what the future may hold for them. 

This report from Denmark follows several others from Scandinavia in which the outcomes of preterm infants born more than two decades ago are described.  They took advantage of national registries that recorded all births in the country and were able to link birth data with subsequent vital statistics for each individual.  They compared the characteristics of young adults who had been born at less than 33 weeks' gestation in the mid-1970s to those that had been born at term.  Data completeness was very high.  They found that, as a group, those who had been born preterm had higher rates of CP, lower educational levels, lower incomes, a higher level of unemployment and higher dependence on social benefits.  Only five percent of young adults in both groups were still living with their parents (must be a Danish thing!) but those born preterm were more likely to be living alone and to be without children.

So what does all this mean?  Interestingly, although the differences are highly statistically significant due to the huge sample size, the absolute differences were not large and the clinical importance of these differences is debatable.  The authors of this paper and Saroj Saigal and David Streiner who provide an accompanying editorial, are quite optimistic.  Although those born preterm are more likely to have medical and developmental challenges than those born at term, they  conclude that the majority who reach adulthood are well-integrated into society and perceive themselves to be healthy and with a good quality of life.

Keep in mind that this report and the others from Norway and Sweden may not be generalizable to the survivors of modern NICU care in North America, especially those of extremely low gestational ages.  However, improvements in many aspects of our care that have occurred over the past 3 decades should give us hope that an even higher proportion of NICU survivors should become happy, independent, functional citizens when they reach adulthood.

Michael Dunn