Abstract
Dr. David Barker hypothesized that low birth weight (LBW) is the result of inadequate fetal nutrition, leading to increased risk of cardiovascular disease (CVD) in the offspring. This hypothesis has stimulated thousands of reports on low birth weight (LBW) and CVD risk. One problem with this association is that many LBW infants are small because they are preterm, not growth-restricted. A second problem is that maternal CVD risk factors confound the association. In an accompanying article, Lu et al. (Am J Epidemiol. 2023;192(6):866-877) address both concerns. Using population data from Sweden and Denmark, the authors estimated CVD incidence among offspring born small for gestational age (SGA). The smallest 3% had a CVD hazard ratio of 1.44 (95% confidence interval: 1.38, 1.51). Even this moderate risk mostly evaporated in sibship analysis, which controlled for unmeasured maternal CVD risk factors (hazard ratio = 1.11, 95% confidence interval: 0.99, 1.25). The risk highlighted by Barker is negligible, especially when compared with a more urgent health issue-cardiovascular risk in women with pregnancy complications. Mothers of SGA infants have up to a 3-fold CVD risk, and mothers with preeclampsia and preterm delivery have up to a 9-fold risk. Pregnancy complications thus provide an early marker of a woman's propensity to develop CVD, and perhaps an opportunity for early intervention. From a public health perspective, Barker's hypothesis about CVD risk in LBW offspring is less compelling than the question of CVD risk among mothers with pregnancy complications. This article is part of a Special Collection on ABC.