The Intergenerational Transmission of Low Birth Weight and Intrauterine Growth Restriction: A Large Cross-generational Cohort Study in Taiwan.

Objectives Our research provides evidence on the intergenerational fetal programming effect by examining associations in the low birth weight (LBW, birth weight <2500 g) and intrauterine growth restriction (IUGR) status between two adjacent generations from both the maternal and paternal sides. Methods Birth certificate data of the entire Taiwanese population are used to construct three-consecutive-generational samples. The final samples consist of the third-generation children born during 1999-2006 to at least one second-generation (G2) parent born during 1978-1985. Maternal and paternal samples are distinguished based on the gender of G2. We first fit the samples with linear probability models while including extensive explanatory variables to control for myriad confounding factors. We then include G2 sibling fixed effects to account for family-specific heterogeneity. Alternative explanations of sample selection, parents' assortative mating, and grandmothers' postnatal investment are examined. Results We find that significant intergenerational associations in LBW and IUGR only occur matrilineally. Children born to LBW mothers are 2.28 (95% CI, 0.71-3.85; p < 0.01) percentage points, corresponding to 36%, more likely to be LBW compared to children born to non-LBW mothers who are sisters. These associations cannot be explained by the above alternative explanations. Conclusions Under G2 sibling comparisons, children born to LBW (IUGR) mothers are more likely to be LBW (IUGR), but children born to LBW (IUGR) fathers are not. The findings suggest that maternal health is pertinent and that socio-economic interventions may not yield the desired outcomes within a short period of time.