Risk Of Instrumental Vaginal Delivery Research Articles

Factors Associated With an Increased Risk of Instrumental Vaginal Delivery in Women With Epidural Analgesia for Labor: A Retrospective Cohort Study

(Eur J Anaesthesiol. 2021;38:1059–1066) Although epidural analgesia is an effective and common method of pain management during labor and delivery, studies suggest there may be an increased risk of instrumental vaginal delivery (IVD, forceps or vacuum extractor) use. Instrumental delivery increases risk of maternal and neonatal morbidity and outcomes. This study aimed to identify women at increased risk of instrumental delivery and strategies to decrease associated maternal and neonatal morbidity.

Obstetric Anal Sphincter Injuries (OASIS) in Multiparous Women With the Use of Epidural Anaesthesia: A Retrospective Cohort Study

(Aust N Z J Obstet Gynaecol. 2021;61:30–34) Epidural anesthesia is the gold standard for managing labor pain. But it is also associated with longer second stage of labor and an increased risk of instrumental vaginal delivery, which can lead to obstetric anal sphincter injuries (OASIS). The risk of OASIS is 5.7% in women giving birth for the first time, compared with 1.5% in multiparous women with no history of OASIS. The aim of this study was to evaluate the impact of epidural use in multiparous women on the rates of OASIS and other outcomes.

Factors associated with an increased risk of instrumental vaginal delivery in women with epidural analgesia for labour: A retrospective cohort study.

Epidural analgesia is the most effective form of labour analgesia, but is associated with an increased risk of instrumental delivery. To evaluate factors that are associated with an increased risk of instrumental delivery. Retrospective cohort data study. Singapore's major public maternity institution. All obstetric patients who received labour epidural analgesia for vaginal delivery between January 2012 to December 2015. None. Our primary outcome was the incidence of instrumental delivery. Out of 17 227 pregnant women who received labour epidural analgesia, 12% (n = 2069) had instrumental delivery. Independent factors associated with an increased risk of instrumental delivery included maternal factors [nulliparity (adjusted odds ratio (aOR) 2.97, 95% CI 2.61 to 3.39, P < 0.0001] and advanced maternal age (aOR 1.04, 95% CI 1.03 to 1.05, P < 0.0001)). Greater maternal height (aOR 0.18, 95% CI 0.08 to 0.40), P < 0.0001) was associated with a reduced risk of instrumental delivery. Significant labour-related factors increasing the risk of an instrumental delivery were the use of prostin (aOR 1.19, 95% CI 1.07 to 1.32, P = 0.0014), pre-epidural analgesia (aOR 1.16, 95% CI 1.05 to 1.28, P = 0.0040), a longer second stage of labour (aOR 1.23, 95% CI 1.20 to 1.26, P < 0.0001), higher infant birth weight (aOR 1.27, 95% CI 1.12 to 1.43, P = 0.0002) and an epidural performed by a senior anaesthetist (aOR 1.94, 95% CI 1.72 to 2.18, P < 0.0001). Labour epidural-related factors for an increased risk of instrumental delivery were the occurrence of breakthrough pain (aOR 1.55, 95% CI 1.37 to 1.76, P < 0.0001), a more dense motor block (aOR 1.14, 95% CI 1.03 to 1.25, P = 0.0097) and having an epidural infusion stopped at full cervical dilatation (aOR 1.18, 95% CI 1.05 to 1.32, P = 0.0048) [receiver operating characteristic (ROC) = 0.75]. The multivariate model generated would help identify women at higher risk of instrumental delivery, which can help clinicians to address potentially modifiable factors and improve clinical care.

Programmed Intermittent Epidural Bolus Technique for Maintenance of Labor Analgesia: Does It Work for Everyone?

(Br J Anaesth. 2019;123:e190–e193) Care providers have always worked to provide adequate pain management during childbirth, and neuraxial labor analgesia has been found to be the most effective method of pain relief. Because this delivery method is maintained over long periods of time during labor and delivery, there has been much discussion on the effect of labor analgesia on labor outcomes. While neuraxial labor analgesia has not been found to elevate the risk of cesarean delivery, there is a greater risk for instrumental vaginal delivery due to motor block of the abdominal or pelvic muscles. Wong and colleagues argued that there are many factors involved with epidural analgesia such as anesthetic agents, adjuvant drugs, differing dosages, and various maintenance techniques, and that altering these factors to meet individual needs can reduce the risk of instrumental vaginal delivery and improve labor outcomes.

Epidural Analgesia for Labor Pain

Compared with other types of analgesia or no analgesia, epidurals offered better pain relief, but were associated with a longer second stage of labor and increased risk of instrumental vaginal delivery, maternal fever, and oxytocin (Pitocin) administration. There were no statistically significant differences in overall rates of cesarean delivery, Apgar scores, admission to the neonatal intensive care unit, and maternal satisfaction. Few studies evaluated epidural analgesia in induced labors.

Upright Versus Lying Down Position in Second Stage of Labor in Nulliparous Women With Low Dose Epidural: BUMPES Randomized Controlled Trial

(BMJ 2017;359:j4471) Epidural analgesia is the most effective and preferred form of pain relief in labor for many woman. However, some studies have reported an association between epidural analgesia and a prolongation of the second stage of labor and an increased risk of instrumental vaginal delivery. The concentration of local anesthetic used in many of these studies was greater than is commonly used today, though, resulting in a denser block than that experienced by most women receiving epidural labor analgesia in current practice. Other studies have shown that maternal position during the second stage of labor could also affect the risk of instrumental vaginal delivery. The current study, Birth in the Upright Maternal Position with Epidural in Second Stage (BUMPES) trial, aimed to determine whether being upright during the second stage of labor in nulliparous women receiving low dose epidural analgesia increased the rate of spontaneous vaginal birth compared with women who were lying down.

Intravenous remifentanil patient-controlled analgesia versus intramuscular pethidine for pain relief in labour (RESPITE): an open-label, multicentre, randomised controlled trial

About a third of women receiving pethidine for labour pain subsequently require an epidural, which provides effective pain relief but increases the risk of instrumental vaginal delivery. Remifentanil patient-controlled analgesia (PCA) in labour is an alternative to pethidine, but is not widely used. We aimed to evaluate epidural analgesia progression among women using remifentanil PCA compared with pethidine. We did an open-label, multicentre, randomised controlled trial in 14 UK maternity units. We included women aged 16 years or older, beyond 37 weeks' gestation, in labour with a singleton cephalic presentation, and who requested opioid pain relief. We randomly assigned eligible participants (1:1) to either the intravenous remifentanil PCA group (40 μg bolus on demand with a 2 min lockout) or the intramuscular pethidine group (100 mg every 4 h, up to 400 mg in 24 h), using a web-based or telephone randomisation service with a minimisation algorithm for parity, maternal age, ethnicity, and mode of labour onset. Because of the differences in routes of drug administration, study participants and health-care providers were not masked to the group allocation. The primary outcome was the proportion of women who received epidural analgesia after enrolment for pain relief in labour. Primary analyses were unadjusted and analysed by the intention-to-treat principle. This study is registered with the ISRCTN registry, number ISRCTN29654603. Between May 13, 2014, and Sept 2, 2016, 201 women were randomly assigned to the remifentanil PCA group and 200 to the pethidine group. One participant in the pethidine group withdrew consent, leaving 199 for analyses. The proportions of epidural conversion were 19% (39 of 201) in the remifentanil PCA group and 41% (81 of 199) in the pethidine group (risk ratio 0·48, 95% CI 0·34-0·66; p<0·0001). There were no serious adverse events or drug reactions directly attributable to either analgesic during the study. Intravenous remifentanil PCA halved the proportion of epidural conversions compared with intramuscular pethidine. This finding challenges routine pethidine use as standard of care in labour. National Institute for Health Research Clinician Scientist Award.

Upright Versus Lying Down Position in Second Stage of Labour in Nulliparous Women With Low Dose Epidural: BUMPES Randomised Controlled Trial

(Abstracted from BMJ 2017;359:j4471) Epidural analgesia is the most effective and preferred form of pain relief in labor; however, it can lead to the prolongation of the second stage of labor and also increase the risk of instrumental vaginal delivery. Maternal position during the second stage of labor could also affect the risk of instrumental vaginal delivery.

Perinatal mortality associated with induction of labour versus expectant management in nulliparous women aged 35 years or over: An English national cohort study

BackgroundA recent randomised controlled trial (RCT) demonstrated that induction of labour at 39 weeks of gestational age has no short-term adverse effect on the mother or infant among nulliparous women aged ≥35 years. However, the trial was underpowered to address the effect of routine induction of labour on the risk of perinatal death. We aimed to determine the association between induction of labour at ≥39 weeks and the risk of perinatal mortality among nulliparous women aged ≥35 years.Methods and findingsWe used English Hospital Episode Statistics (HES) data collected between April 2009 and March 2014 to compare perinatal mortality between induction of labour at 39, 40, and 41 weeks of gestation and expectant management (continuation of pregnancy to either spontaneous labour, induction of labour, or caesarean section at a later gestation). Analysis was by multivariable Poisson regression with adjustment for maternal characteristics and pregnancy-related conditions. Among the cohort of 77,327 nulliparous women aged 35 to 50 years delivering a singleton infant, 33.1% had labour induced: these women tended to be older and more likely to have medical complications of pregnancy, and the infants were more likely to be small for gestational age.Induction of labour at 40 weeks (compared with expectant management) was associated with a lower risk of in-hospital perinatal death (0.08% versus 0.26%; adjusted risk ratio [adjRR] 0.33; 95% CI 0.13–0.80, P = 0.015) and meconium aspiration syndrome (0.44% versus 0.86%; adjRR 0.52; 95% CI 0.35–0.78, P = 0.002). Induction at 40 weeks was also associated with a slightly increased risk of instrumental vaginal delivery (adjRR 1.06; 95% CI 1.01–1.11, P = 0.020) and emergency caesarean section (adjRR 1.05; 95% CI 1.01–1.09, P = 0.019). The number needed to treat (NNT) analysis indicated that 562 (95% CI 366–1,210) inductions of labour at 40 weeks would be required to prevent 1 perinatal death. Limitations of the study include the reliance on observational data in which gestational age is recorded in weeks rather than days. There is also the potential for unmeasured confounders and under-recording of induction of labour or perinatal death in the dataset.ConclusionsBringing forward the routine offer of induction of labour from the current recommendation of 41–42 weeks to 40 weeks of gestation in nulliparous women aged ≥35 years may reduce overall rates of perinatal death.

A multicentre, randomised controlled trial of position during the late stages of labour in nulliparous women with an epidural: clinical effectiveness and an economic evaluation (BUMPES).

Epidural analgesia leads to increased risk of instrumental vaginal delivery (IVD). There is debate about whether or not posture in second-stage labour influences the incidence of spontaneous vaginal birth (SVB). In nulliparous women with epidural analgesia, does a policy of adopting an 'upright position' throughout second-stage labour increase the incidence of SVB compared with a policy of adopting a 'lying-down' position? Two-arm randomised controlled trial. Maternity units in England and Wales. Nulliparous women aged ≥ 16 years, at ≥ 37 weeks' gestation with singleton cephalic presentation and intended SVB, in second-stage labour with an epidural providing effective pain relief. (1) Upright position to maintain the pelvis in as vertical a plane as possible; and (2) lying-down position to maintain the pelvis in as horizontal a plane as possible. The primary outcome measure was incidence of SVB. Secondary outcomes included augmentation, interventions to maintain blood pressure, duration of labour, episiotomy, genital tract trauma, post-partum haemorrhage, maternal satisfaction, neonatal metabolic acidosis, 5-minute Apgar score of < 4, resuscitation at birth and admission to neonatal unit. At 1 year for (1) women: urinary or faecal incontinence, dyspareunia and health-related quality of life; (2) for infants: major morbidity. A cost-consequences analysis with a time horizon of 1 year after the birth from a NHS perspective. Between October 2010 and January 2014, 3236 women were randomised from 41 centres in England and Wales. There was a statistically significant difference in the incidence of SVB between groups, with 35.2% of women achieving a SVB in the upright group, compared with 41.1% in the lying-down group (adjusted risk ratio 0.86, 95% confidence interval 0.78 to 0.94). There was no evidence of differences in most of the secondary maternal or neonatal outcomes, or in long-term outcomes at the 12-month follow-up. No significant overall cost differences were observed between upright and lying-down positions for mothers or their babies. Measurement of adherence was challenging in this unmasked trial, and adherence could be influenced by midwives' beliefs about the allocated positions. If adherence was poor, this would have diluted the difference between the two groups. There is clear evidence of the benefit of adopting a lying-down position in second-stage labour in nulliparous women with epidural analgesia, with no apparent disadvantages in either short- or long-term outcomes for mother or baby, and this is cost neutral for the NHS. Questions remain about whether or not other positions could increase the incidence of SVB further in this group of women. The results also raise questions about the role of maternal position in second-stage labour in women without an epidural. Current Controlled Trials ISRCTN35706297. This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in Health Technology Assessment, Vol 21, No. 65. See the NIHR Journals Library website for further project information.

Routine Labor Epidural Analgesia Versus Labor Analgesia on Request

(BJOG. 2015;122(3):344–50) Epidural analgesia (EA) offers the most effective pain relief during labor, but it is also associated with some adverse effects. Specifically, labor EA is associated with an increased risk of instrumental vaginal delivery (IVD), although not with an increased risk of cesarean section (CS). However, given that there is a correlation between women who have a strong need for pain relief and failure of progress in labor, it is not clear whether this increase in IVD is actually caused by EA or is merely a confounder in patients with abnormal labor.

The effect of adding a background infusion to patient-controlled epidural labor analgesia on labor, maternal, and neonatal outcomes: a systematic review and meta-analysis.

Patient-controlled epidural analgesia (PCEA) has gained popularity, but it is still unclear whether adding a background infusion confers any benefit. A systematic literature search in PubMed, Embase, CINAHL, LILACS, CENTRAL, Clinicaltrials.gov, and ISI WOS was performed to identify randomized controlled double-blind trials that compare PCEA-only with PCEA combined with a continuous infusion (PCEA + CI) in parturients. The data were subjected to meta-analyses using the random-effects model. Our primary outcome was the incidence of instrumental vaginal delivery. Secondary outcomes were incidences of spontaneous vaginal and cesarean deliveries, duration of labor, analgesic outcomes, maternal outcomes (visual analog scale scores for pain, maternal satisfaction, nausea, pruritus, hypotension), and neonatal outcomes (Apgar score, umbilical artery pH). We identified 7 trials with a low risk of bias, reporting on 891 parturients, for inclusion in our systematic review. The risk of instrumental vaginal delivery was increased in the PCEA + CI group, risk ratio (RR) 1.66 (95% confidence interval 1.08-2.56, P = 0.02; I = 0%); the RR for cesarean delivery was 0.83 (95% confidence interval 0.61-1.13, I = 0%). The second stage of labor was prolonged (weighted mean difference 12.3 minutes, 95% confidence interval 5.1-19.5 minutes, P = 0.0008; I = 0%) in the PCEA + CI group. Fewer patients in the PCEA + CI group required physician-administered boluses (RR 0.35 [95% confidence interval 0.25-0.47, P < 0.00001; I = 0%]). No differences regarding maternal adverse events (nausea, pruritus, hypotension) or neonatal outcomes (Apgar scores <7, umbilical artery pH) were observed. On the basis of current evidence, no conclusion can be drawn regarding the risks or benefits of adding a continuous background infusion to PCEA compared with PCEA-only epidural labor analgesia. Further high-quality studies involving a sufficient number of patients are required.

Advances in labor analgesia.

The pain of childbirth is arguably the most severe pain most women will endure in their lifetimes. The pain of the early first stage of labor arises from dilation of the lower uterine segment and cervix. Pain from the late first stage and second stage of labor arises from descent of the fetus in the birth canal, resulting in distension and tearing of tissues in the vagina and perineum. An array of regional nerve blocks, systemic analgesic, and nonpharmacologic techniques are currently used for labor analgesia. Nonpharmacologic methods are commonly used, but the effectiveness of these techniques generally lacks rigorous scientific study. Continuous labor support has been shown to decrease the use of pharmacologic analgesia and shorten labor. Intradermal water injections decrease back labor pain. Neuraxial labor analgesia (most commonly epidural or combined spinal-epidural) is the most effective method of pain relief during childbirth, and the only method that provides complete analgesia without maternal or fetal sedation. Current techniques commonly combine a low dose of local anesthetic (bupivacaine or ropivacaine) with a lipid soluble opioid (fentanyl or sufentanil). Neuraxial analgesia does not increase the rate of cesarean delivery compared to systemic opioid analgesia; however, dense neuraxial analgesia may increase the risk of instrumental vaginal delivery.

Factors influencing delivery mode for nulliparous women with a singleton pregnancy and cephalic presentation during a 17-year period

Objective To evaluate the effects of maternal age, induction of labour, epidural analgesia and birth weight on mode of delivery in nulliparous women with a singleton pregnancy and cephalic presentation at ≥36 weeks gestation, and to describe how these factors and their influence have changed over a 17-year period from 1989 to 2005. Study design The study was conducted in the obstetric department of a university teaching hospital in Ireland. Of 45,647 women delivered, 14,867 were nulliparous with a singleton pregnancy and cephalic presentation and undergoing labour at ≥36 weeks gestation, and were included in the study. The main outcome measures were the influence of maternal age, induction of labour, epidural analgesia and birth weight on the mode of delivery. Multinomial logistic regression analysis for type of delivery and the associated explanatory variables and trend analysis of these variables were performed. Results There was a significant progressive increase in both unplanned abdominal delivery and instrumental vaginal delivery, with advancing maternal age. Induction of labour increased the risk of unplanned abdominal delivery (OR 1.92; 95% CI 1.73–2.14). Epidural analgesia was associated with an increased risk of instrumental vaginal delivery (OR 4.68; 95% CI 4.18–5.25), and unplanned abdominal delivery (OR 2.29; 95% CI 1.98–2.66). Mothers of infants with birth weight ≥4.5 kg were less likely to be delivered by instrumental vaginal delivery (OR 0.60; 95% CI 0.41–0.88), than mothers delivering infants in the 2.50–4.49 kg birth weight category. Between 1989 and 2005 there was a significant increase in maternal age ( P = 0.0001), birth weight ( P = 0.042) and unplanned abdominal delivery rates ( P = 0.0004), and a reduction in instrumental vaginal delivery rates ( P = 0.0013). Conclusions These data demonstrate that the increasing trend of unplanned abdominal delivery in nulliparous women with a singleton pregnancy and cephalic presentation may be partially explained by advancing maternal age, and other obstetric factors also play a significant role.

A Retrospective Case-controlled Study of the Association Between Request to Discontinue Second Stage Labor Epidural Analgesia and Risk of Instrumental Vaginal Delivery

Obstetric Anesthesia Digest: September 2009 - Volume 29 - Issue 3 - p 152-153 doi: 10.1097/01.aoa.0000358425.06348.be

A retrospective case-controlled study of the association between request to discontinue second stage labor epidural analgesia and risk of instrumental vaginal delivery

A retrospective case-controlled study of the association between request to discontinue second stage labor epidural analgesia and risk of instrumental vaginal delivery

A retrospective case-controlled study of the association between request to discontinue second stage labor epidural analgesia and risk of instrumental vaginal delivery

Background Epidural dose is often reduced in the second stage of labor with the intention of improving maternal expulsive efforts and decreasing the need for instrumental vaginal delivery (IVD). We conjectured that parturients requiring IVD would have had more analgesic interventions and requests to decrease analgesic density in the second stage. Methods This retrospective, case-controlled study evaluated parturients with combined spinal-epidural analgesia and IVD over a 22-month period. Data recorded and compared between IVD and spontaneous delivery groups included requests to decrease the density of second stage analgesia and treatment of breakthrough pain. A model was developed from patient characteristics and analgesia interventions to predict the likelihood of IVD. Results Records from 2072 parturients were analyzed. The number of parturients in whom basal epidural infusion rate was decreased during the second stage of labor was greater in the IVD group (146/1021 (14.3%) vs. 51/1051 (4.9%), P < 0.001), as was the number of parturients requiring treatment of breakthrough pain in the first stage of labor. Logistic regression analysis found that treatment for breakthrough pain was the strongest predictor of IVD. Conclusion These results support an association between a request to reduce epidural dose in the second stage of labor, as well as supplemental analgesia for treatment of breakthrough pain, with IVD. It is unclear whether administration of more local anesthetic to treat breakthrough pain results in more dense motor blockade, and hence increases risk of IVD, or whether the decrease in infusion rate reflects obstetricians’ dissatisfaction with the progress of obstructed labor.

Patient-requested Neuraxial Analgesia for Labor

A systematic review, including a meta-analysis, on the timing effects of neuraxial analgesia (NA) on cesarean and instrumental vaginal deliveries in nulliparous women was conducted. Of 20 articles identified, 9 met the inclusion quality criteria (3,320 participants). Cesarean delivery (odds ratio, 1.00; 95% confidence interval, 0.82-1.23) and instrumental vaginal delivery (odds ratio, 1.00; 95% confidence interval, 0.83-1.21) rates were similar in the early NA and control groups. Neonates of women with early NA had a higher umbilical artery pH and received less naloxone. In the early NA group, fewer women were not compliant with assigned treatment and crossed over to the control group. Women receiving early NA for pain relief are not at increased risk of operative delivery, whereas those receiving early parenteral opioid and late epidural analgesia present a higher risk of instrumental vaginal delivery for nonreassuring fetal status, worse indices of neonatal wellness, and a lower quality of maternal analgesia.

Effect of Fetal Position on Second-Stage Duration and Labor Outcome

To evaluate the effect of fetal position on 1) second-stage labor duration and 2) indicators of maternal and neonatal morbidity. A retrospective cohort study was conducted using a database from a previously reported randomized clinical trial. The data set includes 210 women with the fetus in a posterior position, 200 women with the fetus in a transverse position, and 1,198 women with the fetus in an anterior position. Mean durations of the second stage of labor for different fetal positions were compared using Tukey studentized test. A multivariate logistic regression model was performed to examine the determinants of prolonged second-stage duration (>or= 3 hours). Kaplan-Meier survival curves were used to graph and compare the duration of the second stage of labor for spontaneous delivery according to the fetal position at full dilatation and study group. Fetal malposition at full dilatation was associated with a significantly increased risk of instrumental vaginal delivery, cesarean delivery, oxytocin administration before full cervical dilatation, episiotomy, severe perineal laceration, and maternal blood loss of more than 500 mL (all P values < .01). Compared with the occiput anterior positions, there were significant differences in the duration of the second stage of labor, with a mean of 3.1 hours (95% confidence interval [CI] 3.0-3.2) for occiput anterior positions, 3.6 hours (95% CI 3.3-3.9) for occiput transverse positions (P < .05), and 3.8 hours (95% CI 3.5-4.1) for occiput posterior positions (P < .05) in the delayed pushing group. For the early pushing group, means were 2.2 hours (95% CI 2.1-2.3) for occiput anterior positions, 2.5 hours (95% CI 2.3-2.8) for occiput transverse positions (P < .05), and 3.0 hours (95% CI 2.7-3.3) for occiput posterior positions (P < .05). Fetal malposition at full dilatation results in a higher risk of prolonged second stage of labor and increases maternal morbidity indicators. II-2.

Rates of caesarean section and instrumental vaginal delivery in nulliparous women after low concentration epidural infusions or opioid analgesia: systematic review

Objective To compare the effects of low concentration epidural infusions of bupivacaine with parenteral opioid analgesia on rates of caesarean section and instrumental vaginal delivery in nulliparous women.Data sources Medline,...