Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
Department of Anesthesia and Pain Management, and Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
Can J Anaesth. 2020 Jul;67(7):836-846. doi: 10.1007/s12630-020-01615-6. Epub 2020 Mar 18.
The purpose of this study was to investigate myometrial contractility induced by oxytocin in women with advanced maternal age (AMA) and morbid obesity (MO). We hypothesized that both oxytocin-pretreated and oxytocin-naïve myometrial tissues from women of AMA and women who are MO would exhibit poor myometrial contractility compared with women that are younger and of normal body mass index (BMI).
This prospective in vitro study was conducted using myometrial samples obtained from women undergoing elective Cesarean deliveries. Three groups of patient were studied: control (≤ 35 yr; BMI, 20-24.9 kg·m), AMA (≥ 40 yr; BMI, 20-24.9 kg·m), and MO (≤ 35 yr BMI, ≥ 40 kg·m). Each myometrial strip was either pretreated with oxytocin 10 M or left in physiologic salt solution for two hours. This was followed by a dose-response testing to oxytocin (10 M to 10 M), during which contractile parameters were measured. The primary outcome was motility index (MI, amplitude × frequency) of contractions.
The MI of contractions was reduced in oxytocin-pretreated samples when compared with their oxytocin naïve counterparts in control (estimated difference -69%; 95% confidence interval [CI], -82 to -48; P < 0.001) and AMA groups (estimated difference, -44%; 95% CI, -68 to -2; P = 0.07). The MI of contractions was not different between oxytocin naïve and oxytocin-pretreated samples from MO women (estimated difference, -26%; 95% CI, -63 to 49; P = 0.46); however, it was significantly lower in these groups compared with oxytocin-naïve samples from the control group.
Oxytocin pre-treatment reduced myometrial contractility in AMA and control group women compared with their oxytocin-naïve counterparts, as a function of the desensitization phenomenon. Attenuated oxytocin-induced myometrial contractility in MO women in both oxytocin-pretreated and oxytocin-naïve samples suggests that these women have intrinsically reduced uterine contractile ability.
www.clinicaltrials.gov (NCT01865669; registered 28 May, 2013).
本研究旨在探讨催产素诱导高龄产妇（AMA）和病态肥胖（MO）患者子宫收缩的情况。我们假设与年轻且 BMI 正常的女性相比，来自 AMA 和 MO 的催产素预处理和催产素未处理的子宫组织都会表现出较差的子宫收缩能力。
这项前瞻性的体外研究使用了接受选择性剖宫产的女性获得的子宫组织样本。研究了三组患者：对照组（≤35 岁；BMI，20-24.9kg·m）、AMA 组（≥40 岁；BMI，20-24.9kg·m）和 MO 组（≤35 岁；BMI，≥40kg·m）。每条子宫肌条要么用 10M 催产素预处理，要么在生理盐溶液中放置两小时。随后进行催产素（10M 至 10M）的剂量反应测试，在此期间测量收缩参数。主要结局是收缩的运动指数（MI，振幅×频率）。
与对照组和 AMA 组的催产素未处理样本相比，催产素预处理样本的收缩 MI 降低（对照组的估计差异-69%；95%置信区间[CI]，-82 至-48；P<0.001；AMA 组的估计差异-44%；95%CI，-68 至-2；P=0.07）。MO 组的催产素未处理和预处理样本之间的收缩 MI 无差异（估计差异-26%；95%CI，-63 至 49；P=0.46）；然而，与对照组的催产素未处理样本相比，这些组的收缩 MI 明显降低。
与催产素未处理的对照组和 AMA 组相比，催产素预处理降低了 AMA 和对照组女性的子宫收缩能力，这是一种脱敏现象。在催产素预处理和催产素未处理的样本中，MO 女性的催产素诱导的子宫收缩减弱表明这些女性的子宫收缩能力固有降低。
www.clinicaltrials.gov（NCT01865669；注册于 2013 年 5 月 28 日）。
