Long-term health in individuals born preterm or with low birth weight: A cohort study

Background

To measure the association of prematurity and non-preterm low birth weight (LBW) with several long-term health outcomes.

Methods

We selected adult participants from the Constances cohort. Associations between preterm birth (<37 weeks versus ≥37 weeks) and outcomes were measured using modified Poisson regression with adjustment for participant age and parental history. We used the same modeling methods to measure the association between LBW (i.e., <sex-specific 10th percentile) and outcomes in participants born ≥ 37 weeks. We tested for an interaction between exposures and sex.

Results

Among 30,295 participants, preterm birth (5.2%) was associated with (RR[CI95]): obesity (1.25[1.08–1.46]), hypertriglyceridemia (1.23[1.07–1.42]), high LDL-cholesterol (1.16[1.05–1.28]), high blood pressure (HBP) (1.22[1.08–1.36]), metabolic syndrome (1.35[1.06–1.71]), non-alcoholic fatty liver disease (1.26[1.08–1.47]), allergic and atopic symptoms (1.06[1.01–1.12]), and lack of tertiary education (1.11[1.02–1.20]). Women had a significantly higher risk of hypertriglyceridemia and metabolic syndrome. In non-preterm participants, LBW was associated with prediabetes/diabetes (1.30[1.12–1.52]), HBP (1.22[(1.12–1.33]) and lack of tertiary education (1.13[1.07–1.20]), whereas the risk of obesity (0.83[0.73–0.95]) and abdominal obesity (0.84[0.76–0.93]) was reduced.

Conclusion

Preterm birth and non-preterm LBW are both risk factors for several adult outcomes. However, regarding excess fat storage, their long-term effect seems to be in the opposite direction.

Impact statement

Preterm birth is associated with a higher long-term risk of obesity, whereas low birth weight is not.

This study improves the understanding of the common idea that low birth weight is associated with a long-term risk of obesity, whereas it might depend on the cause of low birth weight.

These findings provide new insights into the difficult distinction between the long-term adverse health effects of preterm birth and low birth weight.