Much literature in the US documents an intergenerational transmission of birthing person and perinatal morbidity in socioeconomically disadvantaged groups. A separate line of work indicates that family cash transfers may improve life chances of low-income families well into adulthood. By exploiting a quasi-random natural experiment of a large family cash transfer among a southeastern American Indian (AI) tribe in rural North Carolina, we examine whether a perturbation in socioeconomic status during childhood improves birthing person/perinatal outcomes when they become parents themselves. We acquired birth records on 6805 AI and non-AI infants born from 1995 to 2018. Regression methods to examine effect modification tested whether the birthing persons American Indian (AI) status and exposure to the family cash transfer during their childhood years corresponds with improvements in birthing person and perinatal outcomes. Findings show an increase in age at childbearing (coef: 0.15 years, 95% confidence interval [CI]: 0.05, 0.25) and a decrease in pre-pregnancy body mass index (BMI; coef: -0.42, 95% CI: -0.76, -0.09) with increased duration of cash transfer exposure during childhood. The odds of large-for-gestational age at delivery, as well as mean infant birthweight, is also reduced among AI births whose birthing person had relatively longer duration of exposure to the cash transfer. We, however, observe no relation with other birthing person/perinatal outcomes (e.g., tobacco use during pregnancy, preterm birth). In this rural AI population, cash transfers in one generation correspond with improved birthing person and infant health in the next generation.

OBJECTIVES: We aim to contribute to the literature reporting tests of selection in utero. The theory of reproductive suppression predicts that natural selection would conserve mechanisms, referred to collectively as selection in utero, that spontaneously abort fetuses unlikely to thrive as infants in the prevailing environment. Tests of this prediction include reports that women give birth to fewer than expected male twins, historically among the frailest of infants, during stressful times. The onset of the COVID-19 pandemic in the United States in Spring 2020 demonstrably stressed the population. We test the hypothesis that conception cohorts in gestation at the onset of the pandemic in the United States yielded fewer than expected live male twin births. METHODS: We retrieved deidentified data on the universe of live births in the United States from the National Center for Health Statistics birth certificate records. We applied Box-Jenkins time-series methods to the twin secondary sex ratio computed for 77 monthly conception cohorts spanning August 2013 to December 2019 to detect outlying cohorts in gestation at the onset of the pandemic. RESULTS: The twin secondary sex ratio fell below expected values in three conception cohorts (i.e., July, September, and October 2019, all p < .05) exposed in utero to the onset of the pandemic. CONCLUSIONS: Our results add to prior findings consistent with selection in utero. The role of selection in utero in shaping the characteristics of live births cohorts, especially during the COVID-19 pandemic, warrants further scrutiny.

BACKGROUND: In the US, non-Hispanic (NH) Black birthing persons show a two-fold greater risk of fetal death relative to NH white birthing persons. Since males more than females show a greater risk of fetal death, such loss in utero may affect the sex composition of live births born preterm (PTB; <37 weeks gestational age). We examine US birth data from 1995 to 2019 to determine whether the ratio of male to female preterm (i.e., PTB sex ratios) among NH Black births falls below that of NH whites and Hispanics. METHODS: We acquired data on all live births in the US from January 1995 to December 2019. We arrayed 63 million live births into 293 conception cohort months of which 2,475,928 NH Black, 5,746,953 NH white, and 2,511,450 Hispanic infants were PTB. We used linear regression methods to identify trend and seasonal patterns in PTB sex ratios. We also examined subgroup differences in PTB sex ratios (e.g., advanced maternal ages, twin gestations, and narrower gestational age ranges). RESULTS: The mean PTB sex ratio for NH Black births over the entire test period (1.06, 95% Confidence Interval [CI]: 1.05, 1.07) is much lower than that for NH white births (1.18, 95% CI: 1.17, 1.19). NH Black PTB sex ratios are especially low for twins and for births to mothers 35 years or older. Only NH white PTB sex ratios show a trend over the test period. CONCLUSIONS: Analysis of over 10 million PTBs reveals a persistently low male PTB frequency among NH Black conception cohorts relative to NH white cohorts. Low PTB sex ratios among NH Black births concentrate among subgroups that show an elevated risk of fetal death. PTB sex ratios may serve as an indicator of racial/ethnic and subgroup differences in fetal death, especially among male gestations.

Pregnancies ending before 26 weeks contribute 1% of births but 40% of infant deaths in the United States. The rate of these periviable births to non-Hispanic (NH) Black women exceeds four times that for NH whites. Small male periviable infants remain most likely to die. NH white periviable males weigh more than their NH Black counterparts. We argue that male infants born from twin gestations, in which one fetus died in utero (i.e., the vanishing twin syndrome), contribute to the disparity. We cannot directly test our argument because vanishing typically occurs before clinical recognition of pregnancy. We, however, describe and find associations that would emerge in vital statistics were our argument correct. Among male periviable singleton births from 288 monthly conception cohorts (January 1995 through December 2018), we found an average NH white advantage of 30 grams (759 grams versus 729 grams). Consistent with our argument, however, cohorts signaling relatively few survivors of the vanishing twin syndrome showed no disparity.

Cash transfer policies have been widely discussed as mechanisms to curb intergenerational transmission of socioeconomic disadvantage. In this paper, we take advantage of a large casino-funded family transfer program introduced in a Southeastern American Indian Tribe to generate difference-in-difference estimates of the link between childrens cash transfer exposure and third grade math and reading test scores of their offspring. Here we show greater math (0.25 standard deviation [SD], p =.0148, 95% Confidence Interval [CI]: 0.05, 0.45) and reading (0.28 SD, p = .0066, 95% CI: 0.08, 0.49) scores among American Indian students whose mother was exposed ten years longer than other American Indian students to the cash transfer during her childhood (or relative to the non-American Indian student referent group). Exploratory analyses find that a mothers decision to pursue higher education and delay fertility appears to explain some, but not all, of the relation between cash transfers and childrens test scores. In this rural population, large cash transfers have the potential to reduce intergenerational cycles of poverty-related educational outcomes.