Improving Neonatal and Maternal Outcome by Inducing Mild Labor before Elective Cesarean Section: The Lacarus Randomized Controlled Trial

Abstract

<b><i>Background:</i></b> Newborns delivered by elective cesarean section (CS) are at higher respiratory risk than those delivered vaginally or by CS proceeded by labor (secondary CS). The oxytocin challenge test (OCT) induces uterine contractions that trigger the release of fetal hormones regulating lung fluid clearance during transition from the uterine to an air-breathing environment. <b><i>Objectives:</i></b> The aim is to summarize current evidence and outline the Lacarus trial protocol. <b><i>Methods:</i></b> Literature review informed the design of a randomized placebo-controlled multicenter trial of OCT preceding elective CS in 1,450 women with a singleton pregnancy due for CS at >35 weeks gestation, without preceding contractions, rupture of the membranes, or antenatal steroids. OCT comprises the infusion of oxytocin 5 IU/500 mL Ringer lactate at a rate of 12 mL/h, doubling every 10 min until inducing 5 uterine contractions per 15-min interval. The primary endpoint is the occurrence of neonatal respiratory morbidity within 24 h after birth. Secondary endpoints include biochemical and physiological parameters of fetal and maternal well-being, such as breastfeeding rate and fetal plasma copeptin concentrations. <b><i>Conclusion:</i></b> This is the first trial to test the hypothesis that oxytocin-induced contractions before elective CS is a promising application of physiologic principles gleaned from natural birth to improve neonatal and maternal outcomes.

Reference Values for Umbilical Artery Lactate by Mode of Delivery and Gestational Age: A Retrospective Observational Study

“…This suggests that low lactate values are not necessarily desirable, and limited perinatal stress may be beneficial for the infant. In fact, there is an ongoing trial examining whether inducing mild fetal stress by administering oxytocin before eCS may reduce the admission rate of newborns [18]. However, trial results need to be awaited before firm conclusions of the potential benefit of mild fetal stress can be drawn.…”

Are children born by cesarean delivery at higher risk for respiratory sequelae?

“…Future studies should include detailed information on the classification of the women during delivery, the exact indication for CD, and the clinical practices applied during childbirth and newborn care. 30,31 Ideally, future research should combine multiple outcome measures (clinical, functional, and biological such as microbiome data) to better understand the underlying pathophysiological mechanisms that link CD with adverse childhood outcomes.…”

Progression of C-reactive protein from birth through preadolescence varies by mode of delivery

“…Continued encouragement of vaginal delivery, in the absence of maternal and fetal indicators for C-section delivery, may promote future health of the offspring. Data from The Lacarus Randomized Controlled Trial, which is studying the induction of mild labor before elective C-section, may hold promise for reducing any longer-term negative sequala of C-section delivery in offspring ( 58 ). There is also a critical need for trials studying if “vaginal seeding” for the restoration of gut microbiota in C-section delivered infants reduces chronic disease risk ( 59 ).…”