The Hispanic paradox in twin pregnancies

Diminished Health Returns of Educational Attainment Among Immigrant Adults in the United States

Objectives: Marginalization-related diminished returns (MDRs) refer to weaker health effects of educational attainment for socially marginalized groups compared to the socially privileged groups. Most of the existing literature on MDRs, however, has focused on marginalization due to race, ethnicity, and sexual orientation. Thus, very limited information exists on MDRs of educational attainment among immigrant populations in the United States. Aims: Building on the MDRs framework and using a nationally representative sample of US adults, we compared immigrant and native-born adults for the effects of educational attainment on psychological distress, self-rated health (SRH), and chronic diseases (CDs). Methods: The 2015 National Health Interview Survey (NHIS) has enrolled 33,672 individuals who were either immigrant (n = 6,225; 18.5%) or native born (n = 27,429; 81.5%). The independent variable (IV) was educational attainment, which was treated as a categorical variable. The dependent variables included psychological distress, SRH, and CDs, all of which were dichotomous variables. Age, gender, race, ethnicity, and region were confounders. Immigration (nativity status) was the moderator. Results: Higher educational attainment was associated with lower odds of psychological distress, poor SRH, and CDs. However, immigration showed a significant statistical interaction with college graduation on all outcomes, which were suggestive of smaller protective effects of college graduation on psychological distress, poor SRH, and CDs for immigrant than native-born adults. Conclusions: In the US, the associations between educational attainment and psychological distress, SRH, and CDs are all weaker for immigrant than native-born adults. To prevent health disparities, it is essential to decompose health inequalities that are due to low educational attainment from those that are due to diminished returns of educational attainment (i.e., MDRs). There is a need to help highly educated immigrant adults secure positive health outcomes, similar to their native-born counterparts. Such changes may require bold and innovative economic, public, and social policies that help immigrant adults to more effectively mobilize their educational attainment to secure tangible outcomes. Elimination of health disparities in the US requires efforts that go beyond equalizing access to education.

Early rapid growth, early birth: accelerated fetal growth and spontaneous late preterm birth

The past two decades in the United States have seen a 24% rise in spontaneous late preterm delivery (34-36 weeks) of unknown etiology. This study tested the hypothesis that fetal growth was identical prior to spontaneous preterm (n = 221, median gestational age at birth 35.6 weeks) and term (n = 3706) birth among pregnancies followed longitudinally in Santiago, Chile. The hypothesis was not supported: Preterm-delivered fetuses were significantly larger than their term-delivered peers by mid-second trimester in estimated fetal weight, head, limb, and abdominal dimensions, and they followed different growth trajectories. Piecewise regression assessed time-specific differences in growth rates at 4-week intervals from 16 weeks. Estimated fetal weight and abdominal circumference growth rates slowed at 20 weeks among the preterm-delivered, only to match and/or exceed their term-delivered peers at 24-28 weeks. After an abrupt growth rate decline at 28 weeks, fetuses delivered preterm did so at greater population-specific sex and age-adjusted birth weight percentiles than their peers from uncomplicated pregnancies (P < 0.01). Growth rates predicted birth timing: one standard score of estimated fetal weight increased the odds ratio for late preterm birth from 2.8 prior to 23 weeks, to 3.6 (95% confidence interval, 1.82-7.11, P < 0.05) between 23 and 27 weeks. After 27 weeks, increasing size was protective (OR: 0.56, 95% confidence interval, 0.38-0.82, P = 0.003). These data document, for the first time, a distinctive fetal growth pattern across gestation preceding spontaneous late preterm birth, identify the importance of mid-gestation for alterations in fetal growth, and add perspective on human fetal biological variability.