Racial/Ethnic Disparities in Inadequate Gestational Weight Gain Differ by Pre-pregnancy Weight

OBJECTIVES: Pre-pregnancy body mass index (BMI) varies by race/ethnicity and modifies the association between gestational weight gain (GWG) and adverse pregnancy outcomes, which disproportionately affect racial/ethnic minorities. Yet studies investigating whether racial/ethnic disparities in GWG vary by pre-pregnancy BMI are inconsistent, and none studied nationally representative populations. METHODS: Using categorical measures of GWG adequacy based on Institute of Medicine recommendations, we investigated whether associations between race/ethnicity and GWG adequacy were modified by pre-pregnancy BMI [underweight (<18.5kg/m(2)), normal weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), or obese (≥30.0 kg/m(2)) ] among all births to Black, Hispanic, and White mothers in the 1979 USA National Longitudinal Survey of Youth cohort (n=6849 pregnancies; range=1-10). We used generalized estimating equations, adjusted for marital status, parity, smoking during pregnancy, gestational age, and multiple measures of socioeconomic position. RESULTS: Effect measure modification between race/ethnicity and pre-pregnancy BMI was significant for inadequate GWG (Wald test p-value=0.08). Normal weight Black (Risk Ratio (RR)=1.34, 95% confidence interval (CI): 1.18, 1.52) and Hispanic women (RR=1.33, 95%CI: 1.15, 1.54) and underweight Black women (RR=1.38; 95% CI: 1.07, 1.79) experienced an increased risk of inadequate GWG compared to Whites. Differences in risk of inadequate GWG between minority women, compared to White women, were not significant among overweight and obese women. Effect measure modification between race/ethnicity and pre-pregnancy BMI was not significant for excessive GWG. CONCLUSIONS: The magnitude of racial/ethnic disparities in inadequate GWG appears to vary by pre-pregnancy weight class, which should be considered when designing interventions to close racial/ethnic gaps in healthy GWG

In Vitro Determination of the Main Effects in the Design of High-Flow Nasal Therapy Systems with Respect to Aerosol Performance

Abstract Introduction The use of concurrent aerosol delivery during high-flow nasal therapy (HFNT) may be exploited to facilitate the delivery of a variety of prescribed medications for inhalation. Until now, a systematic approach to determine the conditions required to yield an optimal emitted dose has not been reported. The aim of this study was to establish the effects of gas flow rate, input droplet size, and nebulizer position on the amount of aerosol exiting the nasal cannula during HFNT and thus becoming available for inhalation. Methods Testing was completed according to a factorial statistical design of experiments (DOE) approach. Emitted dose was characterized with a vibrating mesh nebulizer (Aerogen Solo, Aerogen Ltd) for an adult model of HFNT at three clinically relevant gas flow rates, using three nebulizers producing varying input droplet sizes and placed at two different nebulizer positions. Results Increasing the gas flow rate significantly lowered the emitted dose, with a dose of 7.10% obtained at 10 LPM, 2.67% at 25 LPM, and 1.30% at 40 LPM (p < 0.0001). There was a significant difference in emitted dose between nebulizers with different input droplet sizes, with increasing input droplet size associated with a reduced emitted dose (6.11% with an input droplet size of 3.22 µm, 2.76% with 4.05 µm, and 2.38% with 4.88 µm, p  = 0.0002, Pearson’s r = − 0.2871). In addition, the droplet size exiting the nasal cannula interface was lower than that produced by the aerosol generator for all devices under test. Positioning the nebulizer immediately after the humidification chamber yielded a marginally greater emitted dose (3.79%) than when the nebulizer was placed immediately upstream of the nasal cannula (3.39%). Flow rate, input droplet size, and nebulizer position were at the 0.10 level of significance, indicating that all three factors had significant effects on emitted dose. According to the DOE model, flow rate had the greatest influence on emitted dose, followed by input droplet size and then nebulizer position. Conclusion Our findings indicate that in order to optimize the amount of aerosol exiting the nasal cannula interface during HFNT, it is necessary for gas flow rate to be low and the input droplet size to be small, while the nebulizer should be positioned immediately after the humidification chamber. Funding Aerogen Limited

Impact of maternal and paternal preconception health on birth outcomes using prospective couples’ data in Add Health

PURPOSE: Retrospective studies of preconception health have demonstrated that parents’ health conditions and behaviors can impact a newborn’s birth outcomes and, subsequently, future health status. This study sought to examine the impact of preconception health, measured prospectively, among both mothers and fathers, on two important birth outcomes: birthweight and gestational age. METHODS: Data came from Add Health (the National Longitudinal Study of Adolescent Health), which included interviews with original participants and a subsample of their partners in 2001–02. In 2008, the original respondents again completed an interview for Add Health. For 372 eligible infants born to these couples, birth outcomes (measured in 2008) were regressed on preconception health conditions and behaviors among non-pregnant heterosexual partners (measured in 2001–02). RESULTS: Mean birthweight was 3399 grams, and mean gestational age was 39 weeks. Birthweight was higher for infants born to mothers with diabetes or high blood pressure, and for mothers who drank alcohol at least once per month, and lower for infants born to fathers with diabetes (p < .05). Infant gestational age was marginally lower for infants born to mothers with higher levels of depression (p < .10), and lower for infants born to fathers with diabetes and with higher levels of fast food consumption (p < .05). CONCLUSIONS: Both maternal and paternal preconception health conditions and behaviors influenced infant birth outcomes. Interventions to promote preconception health should focus on prevention of diabetes and high blood pressure, as well as minimizing consumption of alcohol and fast food