Physiological reactivity to acute stress during pregnancy

描述（由申请人提供）：早产，在美国越来越频繁地发生，与重大的家庭负担和估计每年至少260亿美元的社会成本有关。在美国，早产率为12-13%，而其他发达国家为5-9%。持续存在的种族差异助长了这种差异。心理社会压力和相关的生理后遗症可能会导致早产的整体，以及早产的种族差异。慢性压力的经历，如少数民族地位所带来的压力，可能会使生理压力反应敏感。事实上，与白人相比，非洲裔美国人对各种急性应激源表现出更大的心血管反应。重要的是，血压，糖皮质激素，和急性应激的儿茶酚胺反应是衰减在健康的怀孕期间相比，非怀孕。这种适应可以保护母亲和胎儿免受母体生理激活的潜在有害影响。因此，对日常压力源表现出更大和更广泛的生理反应的妇女可能会增加围产期不良结局的风险。值得注意的是，没有关于怀孕期间急性应激的研究检查了炎症免疫反应或血压变化的潜在机制（即，心输出量、总外周阻力）。此外，关于种族对怀孕的生理适应的影响的资料有限。目前的研究将通过检查40名健康孕妇（20名白人，20名非洲裔美国人）和40名人口统计学匹配的非妊娠对照妇女对急性应激的心血管，内分泌和免疫反应来解决文献中的重要空白。这项研究的目的是最终导致确定妇女在更大的风险，围产期的负面结果和阐明的机制，潜在的风险增加，提供个性化的保健服务的基础。具体目标1：利用更全面和先进的方法来评估妊娠期与非妊娠期的生理反应，包括炎症、阻抗心动图和糖皮质激素受体功能的测量。假设#1：与未怀孕的女性相比，怀孕的女性对急性压力的生理反应会减弱。具体目标#2：检查妊娠期与非妊娠期生理反应的种族差异。假设#2：与白人女性相比，非洲裔美国女性在怀孕和非怀孕期间对压力表现出更大的生理反应。具体目标#3：检查妊娠和非妊娠期间生理反应的社会心理相关性。假设#3：报告更大痛苦的女性在怀孕和非怀孕期间会表现出更大的生理反应。具体目标#4：检查生理反应和妊娠时间之间的关联。假设4：对急性应激的生理反应越大，妊娠期越短。公共卫生相关性：这项研究将填补我们在怀孕期间的生理适应和种族对这种适应的影响方面的知识空白。从这项研究中获得的信息将为以下工作提供基础：1）确定围产期不良结局风险更大的妇女; 2）描述压力和早产风险之间联系的生理机制; 3）提供旨在减少压力影响并促进健康妊娠和胎儿发育的干预措施。

DESCRIPTION (provided by applicant): Preterm delivery, an increasingly frequent occurrence in the United States, is associated with significant family burden and an estimated societal cost of at least $26 billion per year. In the U.S., the preterm birth rate is 12-13% as compared to 5-9% in other developed countries. Persistent racial disparities contribute to this discrepancy. Psychosocial stress and related physiological sequelae may contribute to preterm birth overall, as well as to racial disparities in preterm birth. The experience of chronic stress, such as that conferred by racial minority status, may sensitize physiological stress responses. Indeed, as compared to Caucasians, African-Americans exhibit greater cardiovascular reactivity to a variety of acute stressors. Importantly, blood pressure, glucocorticoid, and catecholamine responses to acute stress are attenuated during healthy pregnancy as compared to nonpregnancy. This adaptation may protect the mother and fetus from potentially detrimental effects of maternal physiological activation. Thus, women who exhibit greater and more extended physiological reactions to everyday stressors may be at increased risk for negative perinatal outcomes. Notably, no studies of acute stress during pregnancy have examined inflammatory immune responses or mechanisms underlying blood pressure change (i.e., cardiac output, total peripheral resistance). Moreover, limited information is available regarding effects of race on physiological adaptation to pregnancy. The current study will address important gaps in the literature by examining cardiovascular, endocrine, and immune reactivity to acute stress among 40 healthy pregnant women (20 Caucasian, 20 African-American) and 40 demographically matched nonpregnant control women. This research is designed to ultimately lead to the identification of women at greater risk for negative perinatal outcomes and elucidation of mechanisms underlying increased risk, providing a basis for individualized health care services. Specific Aim #1: To utilize more comprehensive and advanced methodology to assess physiological reactivity during pregnancy versus nonpregnancy, including measures of inflammation, impedance cardiography, and glucocorticoid receptor function. Hypothesis #1: Pregnant women will show attenuated physiological responses to acute stress as compared to nonpregnant women. Specific Aim #2: To examine racial differences in physiological reactivity during pregnancy versus nonpregnancy. Hypothesis #2: As compared to Caucasian women, African-American women will exhibit greater physiological reactivity to stress during pregnancy and nonpregnancy. Specific Aim #3: To examine psychosocial correlates of physiological reactivity during pregnancy and nonpregnancy. Hypothesis #3: Women reporting greater distress will exhibit greater physiological reactivity during pregnancy and nonpregnancy. Specific Aim #4: To examine associations between physiological reactivity and length of gestation. Hypothesis #4: Greater physiological reactivity to acute stress will predict shorter gestational length. PUBLIC HEALTH RELEVANCE: This study will fill important gaps in our knowledge regarding physiological adaption during pregnancy and effects of race on such adaptation. Information gained from this study will provide the groundwork for the following: 1) identification of women at greater risk of negative perinatal outcomes; 2) describing physiological mechanisms underlying the link between stress and risk of preterm delivery; and 3) providing interventions designed to reduce the effects of stress and promote healthy pregnancy and fetal development.