Factors associated with higher oxytocin requirements in labor

Abstract

Objective To identify clinical characteristics associated with high maximum oxytocin doses in women who achieve complete cervical dilation. Methods A retrospective nested case-control study was performed within a cohort of all term women at a single center between 2004-2008 who reached the second stage of labor. Cases were defined as women who had a maximum oxytocin dose during labor >20 mu/min, while women in the control group had a maximum oxytocin dose during labor of ≤20 mu/min. Exclusion criteria included no oxytocin administration during labor, multiple gestations, major fetal anomalies, nonvertex presentation, and prior cesarean delivery. Multiple maternal, fetal, and labor factors were evaluated with univariable analysis and multivariable logistic regression. Results Maximum oxytocin doses >20 mu/min were administered to 108 women (3.6%), while 2864 women received doses ≤20 mu/min. Factors associated with higher maximum oxytocin dose after adjusting for relevant confounders included maternal diabetes, birth weight >4000 gm, intrapartum fever, administration of magnesium, and induction of labor. Conclusions Few women who achieve complete cervical dilation require high doses of oxytocin. We identified maternal, fetal and labor factors that characterize this group of parturients.

Oxytocin administration for induction and augmentation of labour in Polish maternity units– an observational study

“…In low-dose regimens, women received 5.74 µg and while women in high-dose regimens received 7.98 µg [37], higher than the total amount found in our study. Similar to our ndings, Frey et al (2015) found that induction was associated with higher maximum oxytocin doses [38]. The fact that higher amounts of oxytocin were administrated to women following induction of labour is understandable, given that the infusion is likely to be continued for a more extended period.…”

Novel oxytocin receptor variants in laboring women requiring high doses of oxytocin

“…This study corroborated the findings by Frey et al demonstrating that maternal body mass index (BMI), maternal diabetes, and labor induction were risk factors for requiring high doses of oxytocin to achieve delivery 6 . We found that HDR patients were more likely than LDR patients to have cesarean sections for first stage arrest and less likely to have cesarean sections for non-reassuring fetal status.…”

“…These groups were selected because they fell below the 25 th percentile and above the 95 th percentile of oxytocin dose within our population of laboring patients 6 . Our institutional protocol for oxytocin administration allows for either high-dose or low-dose regimens at the discretion of the obstetric provider.…”

“…Frey and colleagues recently identified several risk factors for requiring high doses of oxytocin, including diabetes, intrapartum fever, and large fetal birthweight 6 . However, many women with these risk factors only require low doses of oxytocin, and those without any risk factors may require high doses of oxytocin, indicating an incomplete understanding of the etiologies of high oxytocin dose requirement.…”

Effect of magnesium sulfate on oxytocin-induced contractility in human myometrium: an in vitro study

“…14 The resultant need for a higher oxytocin dose to cause adequate uterine contraction in vivo has also been shown in labouring women who received oxytocin for labour augmentation. 15 Furthermore, there are studies suggesting that use of MgSO 4 may lead to increased requirements for oxytocin 16,17 or that MgSO 4 may increase PPH in preeclamptic patients. 17 Nevertheless, further studies are warranted to assess these potential interactions.…”