What height of block is needed for manual removal of placenta under spinal anaesthesia?

Time to redefine prolonged third stage of labor? A systematic review and meta-analysis of the length of the third stage of labor and adverse maternal outcome after vaginal birth

OBJECTIVE

This study aimed (1) to assess the association between the length of the third stage of labor and adverse maternal outcome after vaginal birth and (2) to evaluate whether earlier manual placenta removal reduces the risk of adverse outcome.

DATA SOURCES

PubMed, MEDLINE, Embase, ClinicalTrials.gov, the Cochrane Library, Journals@Ovid, and the World Health Organization International Clinical Trials Registry were searched from January 1, 2000, to June 13, 2023.

STUDY ELIGIBILITY CRITERIA

All studies that assessed adverse maternal outcome, defined as any maternal complication after vaginal birth, concerning the length of the third stage of labor and the timing of manual placenta removal were included.

METHODS

The included studies were evaluated using the Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology methodology. Pooled odds ratios with 95% confidence intervals were calculated. Heterogeneity (I2 test) was assessed, subgroup analyses were performed, and 95% prediction intervals were calculated.

RESULTS

To meet the first objective, 18 cohort studies were included. The assessed cutoff values for the length of the third stage of labor were 15, 30, and 60 minutes. Women with a third stage of labor of ≥15 minutes had an increased risk of postpartum hemorrhage compared with those with a third stage of labor of <15 minutes (odds ratio, 5.55; 95% confidence interval, 1.74-17.72). For women without risk factors for postpartum hemorrhage, the odds ratio was 2.20 (95% confidence interval, 0.75-6.49). Among women with a third stage of labor of ≥60 minutes vs women with a third stage of labor of <60 minutes, the odds ratio was 3.72 (95% confidence interval, 2.36-5.89). The incidence of red blood cell transfusion was higher for a third stage of labor of ≥30 minutes than for a third stage of labor of <30 minutes (odds ratio, 3.23; 95% confidence interval, 2.26-4.61). Of note, 3 studies assessed the timing of placenta removal and the risk of adverse maternal outcome. However, the results could not be pooled because of the different outcome measures. Moreover, 1 randomized controlled trial (RCT) reported a significantly higher incidence of hemodynamic compromise in women with manual placenta removal at 15 minutes than in women with manual placenta removal at 10 minutes (30/156 [19.2%] vs 10/156 [6.4%], respectively), whereas 2 observational studies reported a lower risk of bleeding among women without manual placenta removal.

CONCLUSION

Although the risk of adverse maternal outcome after vaginal birth increases when the third stage of labor exceeds 15 minutes, there is no convincing supporting evidence that reducing the length of the third stage of labor by earlier manual removal of the placenta can reduce the incidence of adverse maternal outcome.

Anaesthesia/analgesia for manual removal of retained placenta

BACKGROUND

As a retained placenta is a potential life-threatening obstetrical complication, effective and timely management is important. The estimated mortality rates from a retained placenta in developing countries range from 3% to 9%. One possible factor contributing to the high mortality rates is a delay in initiating manual removal of the placenta. Effective anaesthesia or analgesia during this procedure will provide adequate uterine relaxation and pain control, enabling it to be carried out effectively.

OBJECTIVES

To assess the effectiveness and safety of general, regional, and local anaesthesia or analgesia during manual removal of a retained placenta.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform to 30 September 2019, and reference lists of retrieved studies.

SELECTION CRITERIA

We sought randomised controlled trials (RCTs), quasi-randomised controlled trials, and cluster-randomised trials that compared different methods of preoperative or intraoperative anaesthetic or analgesic, administered during the manual removal of a retained placenta.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the study reports for inclusion, and risk of bias, extracted data and checked them for accuracy. We followed standard Cochrane methodology.

MAIN RESULTS

We identified only one randomised controlled trial (N = 30 women) that evaluated the effect of paracervical block on women undergoing manual removal of a retained placenta compared with intravenous pethidine and diazepam. The study was conducted in a hospital in Papua New Guinea. The study was at high risk of bias of performance bias and detection bias, low risk of attrition bias, and an unclear risk of selection bias, reporting bias, and other bias. The included study did not measure this review's primary outcomes of pain intensity and adverse events. The study reported that there were no women, in either group, who experienced an estimated postpartum blood loss of more than 500 mL. We are uncertain about the providers' satisfaction with the procedure, defined as their perception of achieving good pain relief during the procedure (risk ratio (RR) 1.50, 95% confidence interval (CI) 0.71 to 3.16, one study, 30 women; very low quality evidence). We are also uncertain about the women's satisfaction with the procedure, defined as their perception of achieving good pain relief during the procedure (RR 0.82, 95% CI 0.49 to 1.37; one study, 30 women; very low quality evidence). The included study did not report on any of our other outcomes of interest.

AUTHORS' CONCLUSIONS

There is insufficient evidence from one small study to evaluate the effectiveness and safety of anaesthesia or analgesia during the manual removal of a retained placenta. The quality of the available evidence was very low. We downgraded based on issues of limitations in study design (risk of bias) and imprecision (single study with small sample size, few or no events, and wide confidence intervals). There is a need for well-designed, multi-centre, randomised, controlled trials to evaluate the effectiveness and safety of different types of anaesthesia and analgesia during manual removal of a retained placenta. These studies could report on the important outcomes outlined in this review.

Retained placenta: Do we have any option?

Retained placenta is a known cause of post-partum haemorrhage and maternal mortality. A recent systemic review has confirmed that the incidence of retained placenta had increased all over the world, which is more common in developed countries. Failure of retro-placental myometrium contraction is the main cause of retained placenta. Maternal age greater than 35 years, grandmultipara, preterm labor, history of previous retained placenta, and caesarean section were the risk factors for retained placenta. Manual removal of the placenta has been the treatment of choice. Attempts had been made by clinician and researchers to find a safe, effective and reliable method to avoid the need for surgical intervention. The efficacy and safety of prostaglandin, nitroglycerin or acupuncture in the management of retained placenta are yet to be further evaluated. Nonetheless, till date only intra-umbilical vein oxytocin has been studied extensively but with varied success. More randomized clinical trials are needed to address this issue. However, if immediate manual placenta removal service is unavailable, a trial of intra-umbilical vein oxytocin 100 IU at a total volume of at least 40 mL while preparing for transfer to a tertiary center or theatre may result in spontaneous expulsion of the placenta.