ACTIVIN A IN HUMAN PREGNANCY

早产发生在大约10%的怀孕， 对围产期/新生儿发病率和死亡率的影响。 早产儿 占新生儿死亡率的80%以上， 新生儿发病率的最高点 在灵长类动物中已经观察到子宫收缩的昼夜节律 还有人类 值得注意的是，收缩的基础次数似乎增加了 随着胎龄的增加， 夜间子宫收缩力 增加夜间催产素水平， 与子宫收缩，已证明在恒河猴。 未结合的激活素A，被卵泡抑素灭活--其天然结合 蛋白质-在非妊娠女性中未显示。 但据 在怀孕的前三个月检测到， 特别是在分娩时。 在早产的妊娠中， 递送后，激活素A水平也显著增加。 后 递送时，激活素A水平福尔斯迅速下降， 产后6小时后即可检测到。 激活素A也被证明 直接给药后外周增加催产素 下丘脑室旁核，以及结合 含催产素的树突。 当羊膜细胞与 激活素A，前列腺素E2a被诱导。 PGE2a是一种众所周知的 子宫收缩的在这些条件下，激活素A可能发挥重要作用， 在启动真正分娩的级联中，病理性或其他。 本研究将重点关注子宫收缩的昼夜节律模式， 24小时内激活素A、卵泡抑素和催产素水平 不同胎龄的妇女，主要是25 - 27周，30 - 32周， 35 - 37周，40 - 42周。 将以连续间隔采集血液 在24小时内，控制暴露于光和 活动/压力体验。 激活素A、卵泡抑素和 催产素，和子宫收缩将在不同的比较 胎龄

Preterm delivery occurs in approximately 10% of pregnancies, with marked impact on perinatal/neonatal morbidity and mortality. Premature babies account for greater than 80% of neonatal mortalities and greater than 90% of neonatal morbidities in the U.S. A circadian rhythm of uterine contractions has been observed in primates and humans. Notably, a basal number of contractions seems to increase as gestational age inceases, with a particular predisposition to nighttime uterine contractility. Increased nighttime oxytocin levels, with uterine contractions, have been demonstrated in rhesus monkeys. Unbound activin A, inactivated by follistatin--its natural binding protein--is not demonstrated in the nonpregnant female. However, it is detected in the first trimester of pregnancy with marked elevation at term, particularly at parturition. In gestations with preterm labor and delivery, the activin A levels also increase dramatically. After delivery, the activin A level falls quickly and is essentially not detectable after 6 hours postpartum. Activin A has also been shown to increase oxytocin peripherally after direct administration into the paraventricular nucleus of the hypothalamus, as well as binding to oxytocin-containing dendrites. When amnion cells are incubated with Activin A, prostaglandin E2a is induced. PGE2a is a well-know uterotonic. Given these conditions, activin A may play and important role in the cascade that initiates true delivery, pathological or otherwise. This study will focus on the circadian pattern of uterine contractions, activin A, follistatin, and oxytocin levels over a 24 hour period in women of various gestational ages, primarily 25-27 weeks, 30-32 weeks, 35-37 weeks, 40-42 weeks. Blood will be collected at serial intervals over a 24 hour period, controlling exposure to light and amount of activity/stress experiences. The levels of Activin A, Follistatin, and Oxytocin, and uterine contractions will be compared in the different gestational ages.