CONTEXT Birth triggers a large fetal neuroendocrine response, which is more pronounced in infants born vaginally than in those born by elective cesarean section (ECS). The two related peptides arginine vasopressin (AVP) and oxytocin (OT) play an essential role in peripheral and central stress adaptation and have a shared receptor mediating their function. Elevated cord blood levels of AVP and its surrogate marker copeptin, the C-terminal part of AVP prohormone, have been found after vaginal delivery (VD) as compared to ECS, while release of OT in response to birth is controversial. Moreover, AVP, copeptin and OT have not yet been measured simultaneously at birth. OBJECTIVE To test the hypothesis that AVP but not OT levels are increased in infants arterial umbilical cord blood in response to birth stress and to characterize AVP secretion in direct comparison with plasma copeptin. METHODS In a prospective single-center cross-sectional study, we recruited healthy women with a singleton pregnancy and more than 36 completed weeks of gestation delivering via VD or ECS (cesarean without prior uterine contractions or rupture of membranes). Arterial umbilical cord blood samples were collected directly after birth, centrifuged immediately and plasma samples were frozen. Concentrations of AVP and OT were determined by radioimmunoassay and that of copeptin by ultrasensitive immunofluorescence assay. RESULTS A total of 53 arterial umbilical cord blood samples were collected, n = 29 from VD and n = 24 from ECS. Ten venous blood samples from pregnant women without stress were collected as controls. AVP and copeptin concentrations were significantly higher in the VD group than in the ECS group (both p < 0.001), median (range) AVP 4.78 (2.38-8.66) vs. 2.38 (1.79-3.88) (pmol/L), copeptin 1692 (72.1-4094) vs. 5.78 (3.14-17.97), respectively, (pmol/L). In contrast, there was no difference in OT concentrations (pmol/L) between VD and ECS, 6.00 (2.71-7.69) vs. 6.14 (4.26-9.93), respectively. AVP and copeptin concentrations were closely related (Rs = 0.700, p < 0.001) while OT did not show any correlation to either AVP or copeptin. In linear regression models, vaginal delivery and biochemical stress indicators, base deficit and pH, were independent predictors for both AVP and copeptin. OT was not linked to base deficit or pH. CONCLUSION Vaginal birth causes a profound secretion of AVP and copeptin in infants. Whereas AVP indicates acute stress events, copeptin provides information on cumulative stress events over a longer period. In contrast, fetal OT is unaffected by birth stress. Thus, AVP signaling but not OT mediates birth stress response in infants. This unique hormonal activation in early life may impact neurobehavioral development in whole life.

中文翻译：

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加压素而不是催产素对婴儿的出生压力有反应。

背景 出生会引发大量胎儿神经内分泌反应，这种反应在顺产婴儿中比在择期剖宫产 (ECS) 出生的婴儿中更为明显。两种相关的肽精氨酸加压素 (AVP) 和催产素 (OT) 在外周和中枢应激适应中发挥重要作用，并具有介导其功能的共享受体。与 ECS 相比，阴道分娩 (VD) 后发现 AVP 及其替代标志物和肽素（AVP 激素原的 C 末端部分）的脐带血水平升高，而 OT 响应出生时的释放存在争议。此外，尚未在出生时同时测量 AVP、和肽素和 OT。目的 检验婴儿动脉脐带血中 AVP 水平升高而不是 OT 水平升高以应对出生压力的假设，并与血浆和肽素直接比较来表征 AVP 分泌。方法 在一项前瞻性单中心横断面研究中，我们招募了单胎妊娠并通过 VD 或 ECS（没有先前子宫收缩或胎膜破裂的剖宫产）完成妊娠超过 36 周的健康女性。出生后直接收集动脉脐带血样品，立即离心并冷冻血浆样品。AVP和OT的浓度用放射免疫法测定，和肽素的浓度用超灵敏免疫荧光法测定。结果 共采集了 53 份动脉脐带血样本，n = 29 来自 VD，n = 24 来自 ECS。收集了来自无压力孕妇的 10 份静脉血样本作为对照。VD 组的 AVP 和和肽素浓度显着高于 ECS 组（均 p < 0.001），中位数（范围）AVP 4.78 (2.38-8.66) vs. 2.38 (1.79-3.88) (pmol/L)，和肽素 1692 (72.1-4094) 与 5.78 (3.14-17.97) 分别为 (pmol/L)。相比之下，VD 和 ECS 之间的 OT 浓度 (pmol/L) 没有差异，分别为 6.00 (2.71-7.69) 和 6.14 (4.26-9.93)。AVP 和和肽素浓度密切相关（Rs = 0.700，p < 0.001），而 OT 与 AVP 或和肽素没有任何相关性。在线性回归模型中，阴道分娩和生化应激指标、碱基缺乏和 pH 值是 AVP 和和肽素的独立预测因子。OT 与碱基不足或 pH 值无关。结论 阴道分娩导致婴儿大量分泌AVP和和肽素。AVP 指示急性应激事件，而和肽素提供关于较长时期内累积应激事件的信息。相比之下，胎儿 OT 不受出生压力的影响。因此，AVP 信号而不是 OT 介导婴儿的出生应激反应。这种在生命早期的独特荷尔蒙激活可能会影响整个生命中的神经行为发育。