Risk Factors Associated with Miscarriage and Impaired Fecundity among United States Servicewomen during the Recent Conflicts in Iraq and Afghanistan

Does a history of childbirth impact injury prevalence and mental health in female military members?

The effect of parity status on the prevalence and impact of musculoskeletal injury (MSKi) among female Canadian Armed Forces (CAF) members is unknown. This study aims to identify whether a history of childbirth and pregnancy-related complications are associated with MSKi occurrence among female members of the CAF. From September 2020 to February 2021, data were collected via an online questionnaire that assessed MSKi, reproductive health, and barriers to recruitment and retention in the CAF. Actively serving, female members were included in this analysis stratified by parous (n = 313) or nulliparous (n = 435) status. Descriptive analysis and binary logistic regressions were used to identify prevalence and adjusted odds ratios (aOR) of repetitive strain injuries (RSI), acute injuries, and body regions affected. Covariates included in aOR: age, body mass index, and rank. A p value of <0.05 was considered significant and 95% confidence intervals (CI) were reported. Female members with a history of childbirth were more likely to report an RSI (80.9% vs. 69.9%, OR = 1.57, CI: 1.03 to 2.40), and when stratified by body region, were more likely to have an RSI of the wrist (30.0% vs. 20.5%, aOR = 1.62, CI: 1.09 to 2.40), and foot (39.3% vs. 24.1%, aOR = 1.79, CI: 1.24 to 2.59). When compared to the nulliparous group, parity did not influence prevalence of acute injuries. MSKi and mental health perceptions were different for females who experienced postpartum depression, miscarriage, or preterm birth. Childbirth and pregnancy-related complications impact prevalence of some RSI among female CAF members. Thus, specific health and fitness support may be needed for parous female CAF members.

The Millennium Cohort Study: The First 20 Years of Research Dedicated to Understanding the Long-Term Health of US Service Members and Veterans

The Millennium Cohort Study, the US Department of Defense's largest and longest running study, was conceived in 1999 to investigate the effects of military service on service member health and well-being by prospectively following active duty, Reserve, and National Guard personnel from all branches during and following military service. In commemoration of the Study's 20th anniversary, this paper provides a summary of its methods, key findings, and future directions. Recruitment and enrollment of the first 5 panels occurred between 2001 and 2021. After completing a baseline survey, participants are requested to complete follow-up surveys every 3 to 5 years. Study research projects are categorized into 3 core portfolio areas (psychological health, physical health, and health-related behaviors) and several cross-cutting areas and have culminated in more than 120 publications to date. For example, some key Study findings include that specific military service-related factors (e.g., experiencing combat, serving in certain occupational subgroups) were associated with adverse health-related outcomes and that unhealthy behaviors and mental health issues may increase following the transition from military service to veteran status. The Study will continue to foster stakeholder relationships such that research findings inform and guide policy initiatives and health promotion efforts.

Australian Veterans of the Middle East Conflicts 2001–2010: Select Reproductive Health Outcomes Part 2 — Prenatal, Fetal, and Neonatal Outcomes

Background: Following on from Part 1 of these companion articles, which described the maternal and paternal cohort of the Middle East Area of Operations (MEAO) Census Study, this manuscript aims to describe fetal and infant characteristics and outcomes from the self-report data, including live deliveries, stillbirths, all other pregnancy losses, and unknown outcomes.

Methods: A descriptive analysis was performed on the clinical variables where data were reported. Descriptive statistics (means, frequencies, percentiles) were used to describe the occurrence of adverse gestational outcomes. Odds ratios were also calculated for perinatal outcomes. Infant characteristics and outcomes were evaluated using statistical analysis software IBM SPSS v26.

Results: There were 15,417 pregnancies reported by respondents to the MEAO Census Study. Of these, 74% (11,367) resulted in a live delivery, 0.75% in a stillbirth, and 20% in another type of pregnancy loss (ectopic pregnancy, miscarriage, termination). The unadjusted odds of an adverse perinatal outcome were higher in the MEAO Census population than in the general Australian population, notably stillbirth (OR = 3.11, 95% CI 2.56–3.80), perinatal death (OR = 3.80, 95% CI 3.26–4.44), and neonatal death (OR = 5.43, 95% CI 4.27–6.91). There were 499 cases of birth defects reported and 85 cases of childhood cancer in the MEAO population. The unadjusted odds of childhood cancer were slightly higher (OR = 1.7, 95% CI 0.09–3.28) in the MEAO population, and the unadjusted odds of birth defects were lower (OR = 0.52, 95% CI 0.40–0.68). The male:female infant sex ratio of babies born to respondents was 102 (5939 males:5823 females).

Conclusions: The MEAO Census Study presents a generally reassuring picture of reproductive health for women serving in the Australian Defence Force with regards to the risk of pregnancy loss and perinatal outcomes. The increased odds of perinatal and neonatal death and stillbirth are worthy of further study and evaluation, as is the increase in likelihood of childhood cancer in the offspring of MEAO veterans.

Weathering the storm; a review of pre-pregnancy stress and risk of spontaneous abortion

The Weathering Effect is a theory that links stress exposure, over the life-course, with racial disparities in reproductive outcomes, through the effects of social adversity on a woman's body. The concept of maternal "weathering" captures cumulative somatic and psychological adversities that can exacerbate the effects of aging. Much of the evidence for weathering comes from observational studies linking self-report measures with reproductive outcomes. The purpose of this review is to explore biological mechanisms that underlie these observations. We focus on spontaneous abortion because this event is understudied despite evidence of racial disparities in this outcome. Spontaneous abortion is the most common pregnancy failure, and it happens early in pregnancy. Early pregnancy is a time most susceptible to the harmful effects of immune dysregulation that may, in part, result from adversities experienced before pregnancy begins. In exploring these mechanisms, we draw on well-defined signaling processes observed in the stressor-depression relationship. Pro-inflammatory dysregulation, for example, has particular relevance to immunological control occurring early in pregnancy. Early pregnancy immunologic changes affect the trajectories of pregnancy via control of trophoblastic invasion. Within the first few weeks of pregnancy, uterine derived cytokines operate within cytokine networks and play a critical role in this invasion. Programming for pro-inflammatory dysregulation can occur before conception. This dysregulation, brought into early pregnancy, has implications for viability and success of the index pregnancy. These patterns suggest early pregnancy health is susceptible to stress processing pathways that influence this immunologic control in the first six to eight weeks of pregnancy. In this review, we discuss the known mediating role of immune factors in the stressor-depression relationship. We also discuss how adversity experienced before the index pregnancy, or "pre-pregnancy" may influence these pathways, and subsequently influence early pregnancy health. There is a need to understand adversity, experienced before pregnancy, and mechanisms driving the effects of these experiences on pregnancy outcomes. This approach is a useful entry point for understanding racial inequities in pregnancy health through an understanding of differences in exposures to adversity. We hypothesize that spontaneous abortion involves cyclical changes within a woman's reproductive tract in response to stressors that are established well before a woman enters into pregnancy. Furthermore, we propose mechanisms that potentially drive weathering processes relevant to reproductive disparities. We also examine what is known about pre-pregnancy stress exposures associated with race, inequity, and adversity, and their potential impact on neuroendocrine and immune changes affecting early pregnancy risk.

Deployment and Preterm Birth Among US Army Soldiers

With increasing integration of women into combat roles in the US military, it is critical to determine whether deployment, which entails unique stressors and exposures, is associated with adverse reproductive outcomes. Few studies have examined whether deployment increases the risk of preterm birth; no studies (to our knowledge) have examined a recent cohort of servicewomen. We therefore used linked medical and administrative data from the Stanford Military Data Repository for all US Army soldiers with deliveries between 2011 and 2014 to estimate the associations of prior deployment, recency of deployment, and posttraumatic stress disorder with spontaneous preterm birth (SPB), adjusting for sociodemographic, military-service, and health-related factors. Of 12,877 deliveries, 6.1% were SPBs. The prevalence was doubled (11.7%) among soldiers who delivered within 6 months of their return from deployment. Multivariable discrete-time logistic regression models indicated that delivering within 6 months of return from deployment was strongly associated with SPB (adjusted odds ratio = 2.1, 95% confidence interval: 1.5, 2.9). Neither multiple past deployments nor posttraumatic stress disorder was significantly associated with SPB. Within this cohort, timing of pregnancy in relation to deployment was identified as a novel risk factor for SPB. Increased focus on servicewomen's pregnancy timing and predeployment access to reproductive counseling and effective contraception is warranted.