Oxytocin administration during spontaneous labor: Guidelines for clinical practice. Chapter 6: Fetal, neonatal and pediatric risks and adverse effects of using oxytocin augmentation during spontaneous labor

Association of Self-Reported Physical Fitness during Late Pregnancy with Birth Outcomes and Oxytocin Administration during Labour-The GESTAFIT Project

We explored (a) the associations between self-reported maternal physical fitness and birth outcomes; (b) whether self-reported maternal physical fitness (PF) is related to the administration of oxytocin to induce or stimulate labour. Pregnant women from the GESTAFIT project randomized controlled trial (n = 117) participated in this prospective longitudinal study. Maternal physical fitness was assessed through the International Fitness Scale at the 34th gestational week. Maternal and neonatal birth outcomes and oxytocin administration were collected from the obstetric medical records. Umbilical arterial and venous cord blood gas were analysed immediately after birth. Self-reported overall fitness, cardiorespiratory fitness, muscular strength and flexibility were not related to any maternal and neonatal birth outcomes (all p > 0.05). Greater speed-agility was associated with a more alkaline arterial (p = 0.04) and venous (p = 0.02) pH in the umbilical cord blood. Women who were administered oxytocin to induce or stimulate labour reported lower cardiorespiratory fitness (p = 0.013, Cohen's d = 0.55; 95% confidence interval (CI): 0.14, 0.93) and flexibility (p = 0.040, Cohen´s d = 0.51; 95% CI: 0.09, 0.89) compared to women who were not administered oxytocin. Greater maternal physical fitness during pregnancy could be associated with better neonatal birth outcomes and lower risk of needing oxytocin administration.

High dose vs. low dose oxytocin for labor augmentation: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare the safety and efficacy between high dose and low dose oxytocin administration for labor augmentation.

METHODS

We searched for the available studies during March 2020 in PubMed, Cochrane Library, Scopus, and ISI Web of science. All randomized clinical trials (RCTs) that assessed safety and efficacy of high dose vs. low dose oxytocin for labor augmentation were considered. The extracted data were entered into RevMan software. Dichotomous and continuous data were pooled as odds ratio (OR) and mean difference (MD) respectively, with the corresponding 95% confidence intervals (CI). Our main outcomes were cesarean delivery rate, spontaneous vaginal delivery rate, uterine hyperstimulation and tachysystole, and labor duration from oxytocin infusion.

RESULTS

Eight RCTs with 3,154 patients were included. High dose oxytocin did not reduce cesarean delivery rate compared to low dose oxytocin (OR=0.76, 95% CI [0.52, 1.10], p=0.15). After solving the reported heterogeneity, high dose oxytocin did not increase the rate of spontaneous vaginal deliveries vs. low dose oxytocin (OR=1.06, 95% CI [0.84, 1.32], p=0.64). Low dose oxytocin was linked to a significant decline in uterine hyperstimulation and tachysystole (p>0.001). A reduction in labor duration was found in high dose oxytocin group over low oxytocin regimen (MD=-1.02 h, 95% CI [-1.77, -0.27], p=0.008).

CONCLUSIONS

We found no advantages for high dose oxytocin over low dose oxytocin in labor augmentation except in reducing labor duration. Low dose oxytocin is safer as it decreases the incidence of uterine hyperstimulation and tachysystole. More trials are needed to confirm our findings.

Oxytocin and emergency caesarean section in a mediumsized hospital in Pakistan: A cross-sectional study

INTRODUCTION

One of the most common complications during labor is prolonged labor (dystocia), which is associated with risks for the mother and fetus. Dystocia is usually treated with oxytocin, which is also used to induce labor. Oxytocin may not have the desired effect of progress and can negatively affect the fetus, thus resulting in an emergency caesarean section (CS). The aim of this study was to describe obstetric practice, use of oxytocin and its association with an emergency CS.

METHODS

A cross-sectional retrospective register study was conducted that included all women who gave birth during 2014 and 2015 at a hospital in a large city in Pakistan.

RESULTS

A total of 6652 women gave birth to 6767 newborns, 66.8% were multiparous and 33.2% primiparous women. Of the primiparous women, 78.9% had a spontaneous vaginal birth, 1.2% an elective CS and 14.4% an emergency CS. Of the multiparous women, 81.9% had a spontaneous vaginal birth, 8.0% an elective CS and 6.7% an emergency CS. Operative vaginal birth was 2.1% among primiparous and 0.2% among multiparous women. Oxytocin for induction or augmentation was administered to 60.0% of primiparous and 30.5% of multiparous women. Oxytocin during the first stage of labor was associated with an increased risk for emergency CS for both primiparous and multiparous women.

CONCLUSIONS

Despite the association between oxytocin and emergency CS, the CS rate was low in this hospital. The majority of the women gave birth vaginally, even with a breech presentation. Few operative vaginal births were performed.

[Oxytocin administration during spontaneous labour: Guidelines for clinical practice. Guidelines short text]

OBJECTIVES

To define the different stages of spontaneous labour. To determine the indications, modalities of use and the effects of administering synthetic oxytocin. And to describe undesirable maternal and perinatal outcomes associated with the use of synthetic oxytocin.

METHOD

A systematic review was carried out by searching Medline database and websites of obstetrics learned societies until March 2016.

RESULTS

The 1st stage of labor is divided in a latence phase and an active phase, which switch at 5cm of cervical dilatation. Rate of cervical dilatation is considered as abnormal below 1cm per 4hour during the first part of the active phase, and below 1cm per 2hours above 7cm of dilatation. During the latent phase of the first stage of labor, i.e. before 5cm of cervical dilatation, it is recommended that an amniotomy not be performed routinely and not to use oxytocin systematically. It is not recommended to expect the active phase of labor to start the epidural analgesia if patient requires it. If early epidural analgesia was performed, the administration of oxytocin must not be systematic. If dystocia during the active phase, an amniotomy is recommended in first-line treatment. In the absence of an improvement within an hour, oxytocin should be administrated. However, in the case of an extension of the second stage beyond 2hours, it is recommended to administer oxytocin to correct a lack of progress of the presentation. If dynamic dystocia, it is recommended to start initial doses of oxytocin at 2mUI/min, to respect at least 30min intervals between increases in oxytocin doses delivered, and to increase oxytocin doses by 2mUI/min intervals without surpassing a maximum IV flow rate of 20mUI/min. The reported maternal adverse effects concern uterine hyperstimulation, uterine rupture and post-partum haemorrhage, and those of neonatal adverse effects concern foetal heart rate anomalies associated with uterine hyperstimulation, neonatal morbidity and mortality, neonatal jaundice, weak suck/poor breastfeeding latch and autism.

CONCLUSION

The widespread use of oxytocin during spontaneous labour must not be considered as simply another inoffensive prescription without any possible deleterious consequences for mother or foetus. Conditions for administering the oxytocin must therefore respect medical protocols. Indications and patient consent have to be report in the medical file.