This is the second part of my latest ‘research decluttering’ exercises, where I give up on the idea of writing you a separate blog post about every study in my ‘to read’ pile, and instead share the contents of the pile with you! Recently, I’ve been focused on looking at studies which help add insight to the question of ‘what helps keep birth normal’, as I’m about to facilitate more workshops on that topic, and here are four more studies which might help us with that question.
Epidurals: do they or don’t they increase caesareans?
My first ‘study’ isn’t a study at all, but an article about a body of research. I love Henci Goer’s writing and analysis, and this is a great article which will help people understand the issues in more depth. Especially recommended for those who don’t have a strong research background but who want to understand the debate.
Abstract: The controversy over whether epidurals increase the risk of cesarean has raged since the 1970s. This article provides a history of the early observational research designed to answer this question and an in-depth analysis of the most recent randomized control trials. Based on the research, the author concludes that we cannot assure women that epidurals do not increase the risk of cesarean.
Goer H, (2015). The Journal of Perinatal Education 24(4): 209-212.
Uterine rupture without previous caesarean delivery: a population-based cohort study
This sounds like a very scary study, doesn’t it?! Although it is somewhat reassuring to women seeking a vaginal birth after a caesarean to find out that uterine rupture can occur even in women having their first baby, I’m never sure that this is a great topic to raise if there is no need to. That’s because the risks sound so scary and yet the chances of a uterine rupture actually happening are really low: actually about 1 in 30303, according to the data gathered in this study. But the reason that I’ve included this paper here is because, although one of the factors associated with rupture (multiparity, but let’s not get overly worried, because the chance of it happening is still incredibly low) isn’t modifiable, two of the factors associated with uterine rupture are modifiable. Those are epidural analgesia and oxytocin augmentation. So this is just one more study which suggests that, unless intervention is truly warranted, less is probably better.
Objective: To determine incidence and patient characteristics of women with uterine rupture during singleton births at term without a previous caesarean delivery.
Study design: Population based cohort study. Women with term singleton birth, no record of previous caesarean delivery and planned vaginal delivery (n = 611,803) were identified in the Danish Medical Birth Registry (1997–2008). Medical records from women recorded with uterine rupture during labour were reviewed to ascertain events of complete uterine rupture. Relative Risk (RR) and adjusted Relative Risk Ratio (aRR) of complete uterine rupture with 95% confidence intervals (95% CI) were ascertained according to characteristics of the women and of the delivery.
Results: We identified 20 cases with complete uterine rupture. The incidence of complete uterine rupture among women without previous caesarean delivery was about 3.3/100,000 deliveries. Multiparity (RR 8.99 (95% CI 1.86–43.29)), induction of labour (RR 3.26 (95% CI 1.24–8.57)), epidural analgesia (RR 10.78 (95% CI 4.25–27.39)), and augmentation by oxytocin (RR 9.50 (95% CI 3.15–28.63)) were associated with uterine rupture. Induction of labour was not significantly related to uterine rupture when adjusted for parity, epidural analgesia and augmentation by oxytocin.
Conclusion: Although uterine rupture is rare, its association with epidural analgesia and augmentation of labour with oxytocin in multipara should be considered. Thus, vigilance should be exercised when labour is obstructed and there is need for epidural analgesia and/or augmentation by oxytocin in multiparous women. Due to the rare occurrence of uterine rupture caution should be exerted when interpreting the findings of this study.
Thisted DLA, Mortensen LH, Krebs L et al (2015). Uterine rupture without previous caesarean delivery: a population-based cohort study. European Journal of Obstetrics & Gynecology and Reproductive Biology. 195: 151-55. doi:10.1016/j.ejogrb.2015.10.013
Judicious use of oxytocin augmentation for the management of prolonged labor
On that same topic, here’s another paper confirming that less oxytocin is better. I still have lots of questions about this area, though, and please read and critique this one carefully and look at the wider questions and issues before discussing with colleagues and clients. It’s a great topic to look at with students.
Introduction: A protocol including judicious use of oxytocin augmentation was investigated to determine if it would change how oxytocin was used and eventually influence labor and fetal outcomes.
Material and Methods: The population of this cohort study comprised 20,227 delivering women with singleton pregnancies ≥37 weeks, cephalic presentation, spontaneous or induced onset of labor, and without previous cesarean section. Women delivering from 2009 to 2013 at Stavanger University Hospital, Norway, were included. Data were collected prospectively. Before implementing the protocol in 2010, oxytocin augmentation was used if progression of labor was perceived as slow. After implementation, oxytocin could only be started when the cervical dilatation had crossed the 4-h action line in the partograph.
Results: The overall use of oxytocin augmentation was significantly reduced from 34.9% to 23.1% (p<0.01). The overall frequency of emergency cesarean sections declined from 6.9% to 5.3% (p<0.05) and the frequency of emergency cesarean sections performed due to fetal distress was reduced from 3.2% to 2.0% (p=0.01). The rate of women with duration of labor over 12 h increased from 4.4% to 8.5% (p<0.01) and more women experienced severe estimated postpartum hemorrhage (2.6% vs. 3.7%; p=0.01). The frequency of children with pH <7.1 in the umbilical artery was reduced from 4.7% to 3.2% (p<0.01).
Conclusions: The frequency of emergency cesarean section was reduced after implementing judicious use of oxytocin augmentation. Our findings may be of interest in the ongoing discussion of how the balanced use of oxytocin for labor augmentation can best be achieved.
Rossen J, Østborg TB, Lindtjørn E et al (2016). Judicious use of oxytocin augmentation for the management of prolonged labor. Acta Obstetricia et Gynecologica Scandinavica. Online ahead of print. 95(3): 355-61. DOI: 10.1111/aogs.12821
Acupressure for inducing labour for nulliparous women with post-dates pregnancy
I am always so torn about studies like this next one! I think the notion of natural induction is an oxymoron, but I understand that some women want induction but not the medical version of it. However, it doesn’t matter what I think about this; my aim with posts like these is to share the evidence and you can look at it for yourself and decide what you think about it! It’s interesting to see sham treatments being used to blind participants to whether or not they are having treatment, but there are always so many questions raised when we try to fit individualised therapies like this into the rigid methodological box that is the randomised controlled trial…
OBJECTIVE: To compare the efficacy of acupressure for induction of labour for nulliparous women with a post-dates pregnancy.
DESIGN: A single-blind randomised trial.
SETTING: Antenatal and labour ward of a UK district general hospital.
PARTICIPANTS: One hundred and thirty two women requiring induction of labour with a post-dates pregnancy (>41 weeks gestation) with no significant medical, obstetric or fetal condition.
METHOD: Acupressure: 20 intermittent presses to stimulate each pair of acupressure points; (Large Intestine 4, followed by Spleen 6) or ‘Sham” treatment: 20 intermittent presses to the patella and then to the olecranon.
MAIN OUTCOME MEASURES: Treatment-to-commencement of labour interval.
SECONDARY OUTCOME MEASURES: Requirements for oxytocin, mode of delivery, duration of labour, requirement for pre-labour Caesarean section, presence of meconium, neonatal intensive care admission, 5 min Apgar scores, and evaluation of maternal satisfaction.
RESULTS: There were no significant differences between the two groups in treatment-to-commencement of labour interval, requirements for oxytocin or mode of delivery. Fewer inductions of labour were required in the sham treatment group (p = 0.004 CI 1-35). The incidence of meconium-stained liquor, and neonatal outcomes were similar for both groups.
CONCLUSIONS: Acupressure performed at 41 weeks gestation in nulliparous women does not appear to be effective for inducing labour for post-dates pregnancy.