Soldiers' resilience? A systematic review of micro-, meso-, and macro-level resilience factors in the military.

Recurrent spontaneous abortion (RSA) is a common pregnancy complication with an incidence rate typically ranging from 1 to 5%. It is defined as the occurrence of two or more spontaneous abortions before 24 or 28 weeks of pregnancy (; ). RSA not only leads to huge psychological and spiritual trauma but also results in adverse outcomes of subsequent pregnancy, such as recurrent miscarriage, pre-eclampsia, and preterm delivery, causing economic burden to the individual, family, and medical system (). RSA Patients are at an elevated risk of experiencing recurrent miscarriages upon subsequent pregnancies with a recurrence risk as high as 70–80%. RSA has multifactorial causes, and currently, 40–50% of cases remain unexplained (). When women with RSA become pregnant again, their previous experiences with pregnancy loss result in heightened expectations for the current pregnancy’s outcome, as well as increased concerns about fetal health and the effectiveness of treatment. However, because the causes of RSA can vary widely, treatment protocols differ significantly among medical institutions. This variability makes it challenging to assess treatment effectiveness and predict fetal development accurately. Compared to women without a history of RSA, those with RSA experience face greater uncertainty regarding the unknowns of pregnancy and their own psychological well-being. This uncertainty has been associated with higher levels of distress, anxiety, and poor birth outcomes (). Excessively high levels of perceived uncertainty may worsen negative emotions in pregnant women, potentially increasing the risk of adverse outcomes such as preterm birth, low birth weight, and pregnancy-related complications (; ; ). Given the correlation between lower psychological well-being and poor perinatal outcomes, more studies are needed to examine the prevalence of uncertainty in RSA patients during subsequent pregnancies. Identifying the factors associated with uncertainty is essential for developing targeted interventions to help mitigate uncertainty. The most commonly used tools for measuring uncertainty included the Mishel Uncertainty in Illness Scale (MUIS) () and the Intolerance of Uncertainty Scale (IUS) (). MUIS primarily measures the cognitive state of individuals dealing with their illness due to a lack of information about their disease, treatment options, and prognosis. In contrast, IUS measures individuals’ cognitive, emotional, and behavioral responses to uncertain situations and future events, reflecting their personality trait of intolerance to uncertainty. For RSA patients who become pregnant again, the greatest challenge they face is not merely the uncertainty of disease information (as measured by the Mishel scale), but also the unknowns regarding the outcome of the future pregnancy, the deep concerns about whether they can successfully carry the baby, and the fears of unexpected events during the entire pregnancy process. This leads to a pervasive sense of negative expectations and overwhelming anxiety about future adverse events. The IUS precisely measures this low tolerance for uncertainty trait.