Project description:BackgroundMaternal overweight and obesity are associated with numerous adverse outcomes including higher rates of maternal and infant mortality and morbidity. Overweight and obesity before, during and after pregnancy are therefore a significant public health priority in England. This project explored and mapped healthy weight service availability at different stages of the childbearing cycle.MethodsA mixed methods approach included a questionnaire-based survey disseminated through Local Maternity Systems and semi-structured interviews or focus groups with providers and commissioners. Current maternal weight service provision was explored along with some of the barriers and facilitators for providing, delivering and accessing healthy weight services. Descriptive statistics were reported for quantitative data and content analysis was used for thematic reporting of qualitative data.ResultsA total of 88 participants responded to the survey. All services were offered most frequently during pregnancy; with healthy eating and/or weight management services offered more often than physical activity services. Few services were targeted specifically at women with a raised body mass index. There was a high degree of inconsistency of service provision in different geographical areas. Several themes were identified from qualitative data including "equity and variation in service provision", "need for rigorous evaluation", "facilitators" to encourage better access or more effective service provision, including prioritisation, a change in focus and co-design of services, "barriers" encountered including financial and time obstacles, poor communication and insufficiently clear strategic national guidance and "the need for additional support".ConclusionsThere is a need to reduce geographical variation in services and the potential health inequalities that this may cause. Improving services for women with a raised body mass index as well as services which encourage physical activity require additional emphasis. There is a need for more robust evaluation of services to ensure they are fit for purpose. An urgent need for clear national guidance so that healthcare providers can more effectively assist mothers achieve a healthy weight gain was identified. Commissioners should consider implementing strategies to reduce the barriers of access identified such as childcare, transport, location and making services free at the point of use.
Project description:ObjectivesThis study aimed to investigate the relationship between night shifts and snacking behaviors during pregnancy using Japanese maternal-infant longitudinal data from a large-scale study.MethodsThis study used the Japan Environment and Children's Study dataset jecs-ta-20190930, released in October 2019. After simple analysis using analysis of variance and multiple comparisons, crude odds ratios (cOR) and adjusted odds ratios (aORs) were calculated. To evaluate eating habits, we examined habitual fast food and snacks (e.g., potato chips, corn puffs and tortilla chips) consumption, midnight snacks, and regular missing breakfast.ResultsThere was no significant association between inappropriate weight gain during pregnancy and night shift work in early pregnancy. The aOR for consuming snacks more than once a week after noticing pregnancy for shift workers was 1.34 (95% confidence interval 1.27-1.41; p < 0.001) compared with worker without night shiftwork. The aOR for shift workers consuming fast food more than three times a week during pregnancy was 1.40 (95% confidence interval 0.79-2.33; p > 0.05).ConclusionsPregnant night shift workers did not show excessive weight gain but had an increased frequency of consumption of snack foods compared with pregnant dayshift workers.
Project description:Background: Maternal leisure time physical activity (LTPA) and sedentary time during pregnancy may influence programming of infant growth in a sex-specific manner. Materials and Methods: Participants (N?=?35,212) from the Danish National Birth Cohort reported moderate/vigorous LTPA (hours/week) in early (conception to mean 16 weeks of gestation) and late pregnancy (mean 31 weeks of gestation to delivery) during interviews at 16 weeks of gestation and 6 months postpartum. Participants reported screen time at work and time spent watching television/videos (hours/day) in early pregnancy. Infant weight at 12 months of age was reported by mothers. Weight-for-length was categorized using sex-specific international standards. Results: Participants reported on average 1 hour per week of early pregnancy moderate/vigorous LTPA, 0.5 hour per week of late pregnancy LTPA, and 3 hours per day of early pregnancy sedentary time. Early pregnancy LTPA category was not associated with infant weight (p for trend?=?0.62). There were suggested associations of early pregnancy sedentary time above the first quartile with greater odds of infant underweight (odds ratio?=?1.15-1.27; p for trend?=?0.27). Associations were similar in male and female infants. Conclusions: There is no clear relationship between early or late pregnancy LTPA and infant weight at 12 months in our study. Maternal early pregnancy sedentary time may be associated with infant underweight at 12 months.
Project description:BackgroundCurrent approaches for establishing public health guidelines on the recommended range of weight gain in pregnancy are subjective and nonsystematic.ObjectiveIn this article, we outline how decision-making on gestational weight-gain guidelines could be aided by quantitative approaches used in noninferiority trials.DesignWe reviewed the theoretical application of noninferiority margins to pregnancy weight-gain guidelines. A worked example illustrated the selection of the recommended range of pregnancy weight gain in women who delivered at the Magee-Womens Hospital, Pittsburgh, PA, in 2003-2010 by identifying weight-gain z scores in which risk of unplanned cesarean delivery, preterm birth, small-for-gestational-age infant, and large-for-gestational-age infant were not meaningfully increased (based on noninferiority margins of 10% and 20%).ResultsIn normal-weight women, lowest risk of adverse perinatal outcome was observed at a weight-gain z score of -0.2 SDs. With a noninferiority margin of 20%, risks of adverse outcome were not meaningfully increased from the -0.2-SD reference value between z scores of -0.97 and +0.33 SDs (which corresponded to 11.3-18.4 kg). In overweight women, the recommended range was much broader: -2.11 to +0.29 SDs (4.4-18.1 kg).ConclusionThe new approach illustrated in this article has a number of advantages over current methods for establishing pregnancy weight-gain guidelines because it is systematic, it is reproducible, and it provides a tool for policy makers to derive guidelines that explicitly reflect values at which risk of adverse outcome becomes meaningfully increased.
Project description:Animal studies suggest a role of vitamin D in fetal lung development although not studied in preterm animals. We tested the hypothesis that vitamin D depletion aggravates respiratory insufficiency in preterm rat offspring. Furthermore, the effects of vitamin D depletion on growth and lung surfactant were investigated. Female Sprague-Dawley rats were randomly assigned low vitamin D (VDL) or control diet before mating and followed with serum 25-hydroxyvitamin D (s-25(OH)D) determinations. After cesarean section at gestational day 19 (E19) or day 22 (E22), placental weight, birth weight, crown-rump-length (CRL), oxygenation (SaO2) at 30 min and survival time were recorded. The pup lungs were analyzed for phospholipid levels, surfactant protein A-D mRNA and the expression of the vitamin D receptor (VDR). S-25(OH)D was significantly lower in the VDL group at cesarean section (12 vs. 30nmol/L, p<0.0001). Compared to the controls, E19 VDL pups had lower birth weight (2.13 vs. 2.29g, p<0.001), lung weight (0.09 vs. 0.10g, p = 0.002), SaO2 (54% vs. 69%, p = 0.002) as well as reduced survival time (0.50 vs. 1.25h, p<0.0001). At E22, the VDL-induced pulmonary differences were leveled out, but VDL pups had lower CRL (4.0 vs. 4.5cm, p<0.0001). The phospholipid levels and the surfactant protein mRNA expression did not differ between the dietary groups. In conclusion, Vitamin D depletion led to lower oxygenation and reduced survival time in the preterm offspring, associated with reduced lung weight and birth weight. Further studies of vitamin D depletion in respiratory insufficiency in preterm neonates are warranted.
Project description:BackgroundObesity affects African American women more than any other group in the US. Pregnancy represents a critical life stage of heightened vulnerability for new or persistent obesity, yet few interventions have been effective in reducing excessive gestational weight gain among African American women. We describe the design and baseline findings of Healthy Babies, a two-arm randomized controlled trial testing a mobile health intervention to minimize excessive gestational weight gain versus usual care in this high risk group.MethodsAfrican American women in early pregnancy were recruited from two large obstetric practices as well as Philadelphia Women, Infants, and Children's clinics. Participants randomized to the intervention received behavior change goals, daily text messages with feedback, web-based weight gain graphs, health coaching, and a Facebook support group. Data collection included baseline (<22 weeks' gestation), 36-38 weeks' gestation, and 6-month postpartum anthropometric measures and assessments of demographics, contextual factors and behavioral targets. The primary outcome was prevalence of excessive gestational weight gain.ResultsAmong participants at baseline (n = 262), the majority met criteria for obesity (63%), were multiparous (62%), single (77%), and were on average 25.6 ± 5.4 years old with a gestational age of 13.9 ± 4.1 weeks. While 82% completed high school, 61% met criteria for inadequate health literacy. Nearly 20% were food insecure. Eighty-eight percent reported a gestational weight gain goal discordant with Institute of Medicine guidelines. There were no significant differences in baseline characteristics between study arms.ConclusionsParticipants represent a high-risk group for excessive gestational weight gain with demonstrated need for intervention.
Project description:BackgroundWhole-systems approaches (WSAs) are well placed to tackle the complex local environmental influences on overweight and obesity, yet there are few examples of WSAs in practice. Amsterdam Healthy Weight Approach (AHWA) is a long-term, municipality-led program to improve children's physical activity, diet, and sleep through action in the home, neighborhood, school, and city. Adopting a WSA, local political, physical, social, educational, and healthcare drivers of childhood obesity are viewed as a complex adaptive system. Since 2013, AHWA has reached >15,000 children. During this time, the estimated prevalence of 2-18-year-olds with overweight or obesity in Amsterdam has declined from 21% in 2012 to 18.7% in 2017. Declining trends are rarely observed in cities. There is a need to formally articulate AHWA program theory in order to: (i) inform future program evaluation which can interpret this decline within the context of AHWA and (ii) contribute a real-life example of a WSA to the literature.MethodsThis study aimed to formally document the program theory of AHWA to permit future evaluation. A logic framework was developed through extensive document review and discussion, during program implementation.ResultsThe working principles of the WSA underpinning AHWA were made explicit in an overarching theory of change, articulated in a logic framework. The framework was operationalized using an illustrative example of sugar intake.ConclusionsThe logic framework will inform AHWA development, monitoring, and evaluation and responds to a wider need to outline the working principles of WSAs in public health.
Project description:BackgroundEarly pregnancy weights are needed to quantify gestational weight gain accurately. Different methods have been used in previous studies to impute early-pregnancy weights. However, no studies have systematically compared imputed weight accuracy across different imputation techniques. This study aimed to compare four methodological approaches to imputing early-pregnancy weight, using repeated measures of pregnancy weights collected from two pregnancy cohorts in Tanzania.MethodsThe mean gestational ages at enrollment were 17.8 weeks for Study I and 10.0 weeks for Study II. Given the gestational age distributions at enrollment, early-pregnancy weights were extrapolated for Study I and interpolated for Study II. The four imputation approaches included: (i) simple imputation based on the nearest measure, (ii) simple arithmetic imputation based on the nearest two measures, (iii) mixed-effects models, and (iv) marginal models with generalized estimating equations. For the mixed-effects model and the marginal model with generalized estimating equation methods, imputation accuracy was further compared across varying degrees of model flexibility by fitting splines and polynomial terms. Additional analyses included dropping third-trimester weights, adding covariate to the models, and log-transforming weight before imputation. Mean absolute error was used to quantify imputation accuracy.ResultsStudy I included 1472 women with 6272 weight measures; Study II included 2131 individuals with 11,775 weight measures. Among the four imputation approaches, mixed-effects models had the highest accuracy (smallest mean absolute error: 1.99 kg and 1.60 kg for Studies I and II, respectively), while the other three approaches showed similar degrees of accuracy. Depending on the underlying data structure, allowing appropriate degree of model flexibility and dropping remote pregnancy weight measures may further improve the imputation performance.ConclusionsMixed-effects models had superior performance in imputing early-pregnancy weight compared to other commonly used strategies.
Project description:BackgroundMaternal prenatal exposure to air pollution has been associated with adverse birth outcomes. However, previous studies focused on a priori time intervals such as trimesters reported inconsistent associations.ObjectivesWe investigated time-varying vulnerability of birth weight to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) using flexible time intervals.MethodsWe analyzed 1,300 live, full-term births from Maternal-Infant Research on Environmental Chemicals, a Canadian prospective pregnancy cohort spanning 10 cities (2008-2011). Daily PM2.5 and NO2 concentrations were estimated from ground-level monitoring, satellite models, and land-use regression, and assigned to participants from pre-pregnancy through delivery. We developed a flexible two-stage modeling method-using a Bayesian Metropolis-Hastings algorithm and empirical density threshold-to identify time-dependent vulnerability to air pollution without specifying exposure periods a priori. This approach identified critical windows with varying lengths (2-363 days) and critical windows that fell within, or straddled, predetermined time periods (i.e., trimesters). We adjusted the models for detailed infant and maternal covariates.ResultsCritical windows associated with reduced birth weight were identified during mid- to late-pregnancy for both PM2.5 and NO2: -6 g (95% credible interval: -11, -1 g) and -5 g (-10, -0.1 g) per µg/m3 PM2.5 during gestational days 91-139 and 249-272, respectively; and -3 g (-5, -1 g) per ppb NO2 during days 55-145.DiscussionWe used a novel, flexible selection method to identify critical windows when maternal exposures to air pollution were associated with decrements in birth weight. Our results suggest that air pollution impacts on fetal development may not be adequately captured by trimester-based analyses.