Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO.
Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO.
Am J Obstet Gynecol. 2022 Aug;227(2):265.e1-265.e8. doi: 10.1016/j.ajog.2022.04.037. Epub 2022 Apr 27.
Fetal acidemia at the time of a scheduled cesarean delivery is generally unexpected. In the setting of reassuring preoperative monitoring, the duration of fetal acidemia in this scenario is presumably brief. The neonatal sequelae and risks associated with brief fetal acidemia in this setting are unknown.
We aimed to assess whether fetal acidemia at the time of a scheduled prelabor cesarean delivery is associated with adverse neonatal outcomes.
This was a retrospective cohort study of singleton, term, nonanomalous, liveborn neonates delivered by scheduled cesarean delivery that was performed under regional anesthesia from 2004 to 2014 at a single tertiary care center with a universal umbilical cord gas policy. Neonates born to laboring gravidas and those whose cesarean delivery was performed for nonreassuring fetal status were excluded. All included patients had reassuring preoperative fetal monitoring. The primary outcome was a composite adverse neonatal outcome that included neonatal death, encephalopathy, therapeutic hypothermia, seizures, intubation, and respiratory distress. This outcome was compared between patients with and those without fetal acidemia (umbilical artery pH <7.2). A multivariable logistic regression was used to adjust for confounders. Cases of fetal acidemia were further characterized as respiratory, metabolic, or mixed acidemia based on additional umbilical cord gas values. Secondary analyses examining the association between the type of acidemia and neonatal outcomes were also performed.
Of 2081 neonates delivered via scheduled cesarean delivery, 252 (12.1%) had fetal acidemia at the time of delivery. Acidemia was more common in breech neonates and in neonates born to gravidas with obesity and gestational diabetes mellitus. Compared with fetuses with normal umbilical artery pH, those with fetal acidemia were at a significantly increased risk for adverse neonatal outcome (adjusted relative risk, 2.95; 95% confidence interval, 2.03-4.12). This increased risk was similar regardless of the type of acidemia.
Even a brief period of mild acidemia is associated with adverse neonatal outcomes at the time of a scheduled cesarean delivery despite reassuring preoperative monitoring. Addressing modifiable intraoperative factors that may contribute to fetal acidemia at the time of a scheduled cesarean delivery, such as maternal hypotension and prolonged operative time, is an important priority to potentially decrease neonatal morbidity in full-term gestations.
计划性剖宫产时胎儿酸中毒通常是出乎意料的。在术前监测令人放心的情况下，这种情况下胎儿酸中毒的持续时间想必很短。在这种情况下，短暂胎儿酸中毒的新生儿后遗症和风险尚不清楚。
我们旨在评估计划性产前剖宫产时胎儿酸中毒是否与不良新生儿结局相关。
这是一项回顾性队列研究，纳入了 2004 年至 2014 年在一家三级保健中心进行的计划性剖宫产分娩的单胎、足月、非畸形、活产新生儿。排除了在分娩时和因胎儿情况不乐观而行剖宫产的产妇所产的新生儿。所有纳入的患者均有令人放心的术前胎儿监测。主要结局是包括新生儿死亡、脑病、治疗性低温、癫痫发作、插管和呼吸窘迫在内的复合不良新生儿结局。将有胎儿酸中毒（脐动脉 pH 值<7.2）的患者与无胎儿酸中毒的患者进行比较。采用多变量逻辑回归来调整混杂因素。根据额外的脐带血气值，将胎儿酸中毒病例进一步分为呼吸性、代谢性或混合性酸中毒。还进行了二次分析，以检查酸中毒类型与新生儿结局之间的关联。
在 2081 例计划性剖宫产分娩的新生儿中，有 252 例（12.1%）在分娩时出现胎儿酸中毒。臀位新生儿和产妇肥胖及患有妊娠期糖尿病的新生儿酸中毒更为常见。与脐动脉 pH 值正常的胎儿相比，酸中毒胎儿发生不良新生儿结局的风险显著增加（校正相对风险，2.95；95%置信区间，2.03-4.12）。无论酸中毒类型如何，这种风险增加都是相似的。
即使是短暂的轻度酸中毒，也与计划性剖宫产时的不良新生儿结局相关，尽管术前监测令人放心。解决可能导致计划性剖宫产时胎儿酸中毒的术中可改变因素，如产妇低血压和手术时间延长，是降低足月妊娠新生儿发病率的重要优先事项。
