Behavioral & Community Health Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2802
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Item EXAMINING THE IMPACT OF PRECONCEPTION AND EARLY PREGNANCY SERUM LEVELS OF MATERNAL VITAMIN D ON CLINICAL MARKERS OF IMPLANTATION AND PREECLAMPSIA(2023) Alkhalaf, Zeina; Thoma, Marie; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Vitamin D is a hormone rather than a vitamin, that is essential for overall health and wellbeing, including but not limited to the reproductive system. Although vitamin D is available through several sources, such as natural ultraviolet sunlight, food, and supplements, low circulating 25-hydroxyvitamin D (25(OH)D) levels of <30 ng/mL are common among pregnant women, with up to 69% of the US population suffering from the condition. Epidemiologic studies have suggested that low maternal serum 25(OH)D levels may be associated with adverse pregnancy outcomes, such as early pregnancy loss and preeclampsia, which may be initiated early in the pregnancy process during implantation and placentation. From a life course perspective, the periconception and early pregnancy period marks a critical time for establishing a healthy pregnancy. Implantation and placentation occur early in pregnancy and involve a complex process that relies on optimal endometrial receptivity and a host of hormonal and immunologic signaling events. Disruptions to this process may be indicated by early clinical markers of pregnancy complications (e.g., vaginal bleeding or subchorionic hemorrhage) and associated with later adverse outcomes (e.g., preeclampsia). In contrast, higher Human Chorionic Gonadotropin (hCG) levels, which have been linked to nausea and vomiting, may be markers of robust implantation and placentation. Therefore, I sought to investigate the preconception and early gestation maternal serum 25(OH)D levels on: (i) vaginal bleeding and subchorionic hemorrhage; (ii) nausea and vomiting; (iii) preeclampsia. In Aim 1, an analysis of medical record documentation of vaginal bleeding and subchorionic hemorrhage found that women who were persistently deficient/insufficient in maternal serum 25(OH)D at both preconception and 8-week gestation had 2.18 times higher (95% CI: 1.13, 4.20) odds of having subchorionic hemorrhage compared to women who remained sufficient across both time periods, even after adjustment for potential confounders. Additionally, an analysis of daily diaries showed women with deficient 25(OH)D levels had a higher odds (OR: 3.02, 95% CI: 1.13, 8.13) of moderate/heavy bleeding versus none compared to women with sufficient 25(OH)D levels based on self-reported daily diaries on vaginal bleeding at the start of pregnancy. In Aim 2, women with persistently deficient 25(OH)D levels at both preconception and early gestation had lower odds (OR: 0.34, 95% CI: 0.20, 0.60) of experiencing nausea and vomiting based on medical records. In comparison, women who increased their 25(OH)D levels early in pregnancy (i.e., were deficient/insufficient at preconception then became sufficient at 8-week gestation) had 1.71 (95% CI: 1.12, 2.61) times higher odds of nausea and vomiting compared to those who were persistently sufficient across both time periods. Based on self-reported nausea and vomiting symptoms from daily diaries, deficient 25(O)D was associated with lower odds (OR 0.65; 95% CI 0.40, 1.06) of both nausea and vomiting when comparing to sufficient 25(OH)D levels. In Aim 3, women who had deficient 25(OH)D at preconception had an increased risk (RR: 1.45, 95% CI: 0.64, 3.29) of preeclampsia (as identified from medical records), although results were insignificant. Linear spline models demonstrated that the risk of preeclampsia declined with each 1 ng/mL increase of 25(OH)D levels up to 40-45 ng/mL (RR: 0.97, 95% CI: (0.93, 1.00), but that levels beyond this threshold show an increase in the risk of preeclampsia for each 1 ng/mL increase in 25(OH)D (RR: 1.03; 95% CI: 1.00, 1.06). This research highlights the importance of exploring the maternal serum levels of 25(OH)D at both preconception and early gestation and how it may affect adverse pregnancy outcomes, such as vaginal bleeding, subchorionic hemorrhage, preeclampsia, and pregnancy outcomes that signify a robust implantation response, such as nausea and or vomiting. It further underscores the importance of assessing maternal serum 25(OH)D levels prior to critical time of implantation and placentation and potential biologic mechanisms that may lead to adverse pregnancy outcomes. Supporting healthy implantation and placentation is of utmost importance as this may guide the remainder of the health of the pregnancy, and any disruption to this process may increase the mother and infant’s risk of maternal morbidity and mortality (e.g., preeclampsia, vaginal bleeding, subchorionic hemorrhage). Future studies are needed with more diverse, larger sample sizes, and both paternal and maternal nutrition to further assess preconception nutritional risk factors on adverse and robust pregnancy outcomes. Accordingly, this research is vital as it may aid in identifying early factors that may reduce adverse maternal and infant health outcomes.Item The Self Reported Health of US Women in the First Postpartum Year: NHANES 2007-2018(2021) Fahey, Jenifer Osorno; Shenassa, Edmond; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Background: Most existing information about the health of US postpartum mothers comes from studies of morbidity and mortality. As a result, relatively little is known about the general well-being of postpartum mothers. Self-rated health (SRH), a single-item, 5-level ordinal measure has been widely used as an indicator of general health status in epidemiologic and population health research. There are no US population studies of maternal SRH in the postpartum period. Methods: An analytic sample of 6,266 women ages 20-44 was created from the 2007-2018 waves of the National Health and Nutrition Surveys. The 5-level SRH measure was dichotomized into “good” and “poor” levels and multivariate logistic regression analysis was used to characterize the relationship between postpartum status and SRH and to test whether parity, cigarette smoking, pregnancy, depression, sleep duration, tiredness/fatigue, obesity, history of c-section and breastfeeding status independently predict poor SRH in the sub-population of postpartum women (n=508). Results: There is a significant relationship between postpartum status and SRH that is moderated by pregnancy status. For women who are not pregnant, postpartum status is associated with lower odds of poor SRH (OR 0.52, 95% CI, 0.34-0.79) while for women who are pregnant, postpartum status is associated with increased odds of poor SRH (OR 2.34, 95% CI 0.81-6.78), an association that did not reach statistical significance at a p=0.05 level. Having a high school education (OR 0.35, 95% CI, 0.13-0.95) breastfeeding (OR 0.22, 95% CI 0.10-0.52) were associated with lower odds of poor SRH, while being Hispanic (OR 3.51, 95% CI 1.20-10.27), tired (OR 2.40, 95% CI 1.08-5.57) or obese (OR 2.72, 95% CI, 1.35-5.56) were associated with higher odds of maternal report of poor health. Discussion: Postpartum status is associated with better SRH. This is not the case; however, for women who are pregnant again in the first postpartum year suggesting that a short interpregnancy interval (IPI) is a threat to postpartum maternal well-being. Breastfeeding, on the other hand, is associated with a strong protective effect on maternal postpartum SRH. These results suggest a need for postpartum contraceptive and breastfeeding promotion efforts that focus on immediate impacts on maternal health. Maternal postpartum obesity and maternal tiredness also emerge as priority areas for maternal postpartum health promotion initiatives. Additional research on the postpartum experience of Hispanic mothers is warranted.Item Estimating the Prevalence and Timing of Events Along the Pathway to Identification of Autism in the US 2016–2018(2021) Hanley, Allison; Nguyen, Quyhn; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The prevalence of autism spectrum disorder (ASD) has risen rapidly in the past decade. Estimates on factors associated with developmental screening and the timing of events along the diagnostic pathway can inform early identification efforts. This dissertation uses cross-sectional data from the 2016–2018 National Survey of Children’s Health to achieve 3 aims: 1) evaluate individual- and state-level sources of variance between states in developmental screening rates via multilevel models, 2) evaluate characteristics associated with the ages at which children with ASD are first diagnosed, receive an intervention plan, and begin intervention, and 3) evaluate differences in lengths of time between these events by cohort. Aim 1: The national rate of developmental screening for children ages 9 months to 5 years is 34.4% (95% Confidence Interval (CI), [34.3, 34.4]). Rates varied between states by 38%. Individual-level factors explained 6% of the variance, while income inequality and a state’s choice to track developmental screening did not explain any variance between states. Aim 2: Linear regression models adjusted for individual and household characteristics showed that compared to children aged 3–5 years at the time of the survey, children 6–11 were 18 months older at first services (? =1.49, 95% CI, [1.18, 1.81] and children aged 12–17 were 38 months older at first ASD diagnosis (? =3.16, 95% CI, [2.72, 3.60]. Aim 3: Analyses using identical models showed that compared to children aged 3–5 at the time of the survey, the interval between first plan and first services was 4 months longer for children 6–11 (? =0.34, 95% CI, [0.07, 0.61]; and 8 months longer between first ASD diagnosis and first services for children aged 12–17 (? =0.67, 95% CI, [0.28, 1.06]. Today’s children with autism receive their first diagnosis, intervention plans, and developmental services at younger ages than in the past and are moving between events with less delay compared to older children. However, the low rate of developmental screening nationwide represents missed opportunities for even earlier identification. Research is needed to identify the macro-level factors that explain the variance between states on developmental screening rates.