BLOOD PRESSURE REGULATION, STRESS AND MATERNAL OXYTOCIN RESPONSE

描述(申请人提供)：分娩后的第一年对许多母亲来说压力很大，但“结合荷尔蒙”催产素(OT)的活性增强可能会降低血压(BP)、交感和皮质酮活性，以及应激行为，同时增加母婴接触期间中央奖励通路的积极影响和激活。目前在美国，大约60%的新妈妈在第一年内重返工作岗位，这增加了母亲的总工作量，同时显著减少了孩子早期母婴接触的时间。在3项翻译研究中，我们发现，在与婴儿温暖接触后的实验室应激源中，降低OT水平的母亲在压力之前、期间和之后的血压水平高于增加OT的母亲；OT降低的母亲比母乳喂养的母亲更有可能是奶瓶喂养的母亲。有婴儿(5个月)的母亲较高的OT反应也与较低的家中动态血压有关。初步数据表明，婴儿不到5个月的非裔美国母亲的OT反应较低可能与提前重返家庭外工作有关。我们假设，在产后第一年，母亲OT活动的减少与母婴之间较少的互动和温暖的身体接触(包括母乳喂养)有关，增加这种接触对母亲和婴儿都是有益的。因此，我们将招募120名母婴双方(其中包括48名非裔美国人)来解决以下问题：1.在产后2-3个月，在温暖的婴儿接触后，与没有重返工作岗位、已经或没有给婴儿断奶的母亲相比，OT反应是否更低？2.事先与婴儿进行身体接触是引发母亲OT增加的必要因素，还是不接触的面对面互动同样有效？3.使用前瞻性的二人组内研究，在2-3个月和1岁时再次测试，在最初的测试中，较高的母亲OT反应是否与家庭中较低的动态血压、较高的母亲依恋得分和更高质量的母婴互动有关，以及它是否预示着1岁时更高质量的互动？所有120名母亲都将接受为期两天的24小时血压监测，以便职场母亲在与婴儿共度的一天与与婴儿分开的一天接受监测。母体催产素反应也将与两天24小时尿儿茶酚胺和皮质醇有关。此外，在试点可行性部分中，母亲和婴儿的唾液和尿液测定将与母亲血液中的催产素同时获得，以提供利用非侵入性获取的样本评估催产素活性的能力的初步测试。这项研究将深入了解早期母婴互动的频率和类型对影响其生理、行为和情感反应的神经行为通路的影响，这可能对母婴的健康和福祉产生深远的影响。

DESCRIPTION (provided by applicant): The first year after childbirth is highly stressful for many mothers, but enhanced activity of the "bonding hormone" oxytocin (OT) may decrease blood pressure (BP), sympathetic and corticosterone activity, and stress behavior, while increasing positive affect and activation of central reward pathways during mother- infant contact. Currently in the US, roughly 60% of new mothers return to work within the first year, increasing the mother's total workload while markedly decreasing the time available for mother-infant contact in the child's early life. In 3 translational studies, we found that mothers who decreased their OT levels during a lab stressor that followed warm contact with their infants had higher BP levels before, during and after stress than mothers who increased OT; OT decrease mothers were more likely to be bottle- than breast- feeders. Higher OT response of mothers with young infants (< 5 months) was also related to lower ambulatory BP at home. Preliminary data suggests that lower OT response in African American mothers with infants less than 5 months old may be linked to early return to work outside the home. We hypothesize that during the first year postpartum, decreased maternal OT activity is related to less frequent mother-infant interactions and less warm physical contact between them (including breast-feeding), and that increasing such contacts are beneficial for both mother and infant. Thus, we will recruit 120 mother-infant dyads (including 48 African American) to address the following questions: 1. At 2-3 months postpartum, is OT response after warm infant contact lower in mothers who have vs. have not returned to work, and who have vs. have not weaned their infants from breast feeding? 2. Is prior physical touch with their infant essential to elicit maternal OT increases, or is face-to-face interaction without touch equally effective? 3. Using a prospective, within-dyad study with testing at 2-3 months and again at 1 year, is higher maternal OT response at initial testing associated with lower ambulatory BP at home, and with higher maternal attachment scores and higher quality mother-infant interaction, and does it predict higher quality interaction at age 1 year? All 120 mothers will undergo 2 days of 24-hour BP monitoring, so that working mothers are monitored on a day spent with vs. a day spent apart from their babies. Maternal OT response will also be related to 24-hour urinary catecholamine and cortisol on both days. Also, in a pilot feasibility component, mother and infant salivary and urinary measures of OT will be obtained concurrently with maternal blood- derived OT, to provide initial tests of the capability to assess OT activity with non-invasively obtained samples. This research will provide insights into the effect of the frequency and type of early mother-infant interactions on neurobehavioral pathways influencing their physiological, behavioral and affective responses, which may have profound implications for the health and well-being of both mother and child.