Pharmacologic intervention for retained placenta: a systematic review and meta-analysis

Racial and ethnic disparities in the incidence, healthcare utilization, and outcomes of retained placenta among delivery hospitalizations in the United States, 2016-2019

BACKGROUND

Retained placenta is a concern during labor and delivery. However, recent data regarding the profiles of retained placenta are scarce, especially nationwide and in minority populations. This study aimed to investigate the recent incidence of retained placenta and its associated outcomes.

METHODS

We retrospectively analyzed an American population-based data from the National Inpatient Sample (NIS) 2016-2019. The outcomes of interest included the incidence of retained placenta, in-hospital mortality, length of hospital stay, and hospitalization costs. We estimated the incidence for retained placenta overall and by racial and ethnic subgroups, utilizing survey weights standardized for each subgroup. Multivariable linear or logistic regression models were employed in our study to investigate the associations between retained placenta and the impact of in-hospital mortality, duration of stay, and hospitalization expenditures for the entire population and further stratified by race and ethnicity, adjusting for potential confounders.

RESULTS

Of the 13,848,131 deliveries, there were 108,035 (or 0.78%) birthing persons were identified as having retained placentas. Over time, the incidence of retained placenta increased from 730 per 100,000 (0.73%) in 2016 to 856 per 100,000 (0.86%) in 2019. Native American mothers have the highest rate of retained placenta, with a prevalence almost twice that of the general population, reaching 1,434 cases per 100,000 (1.43%). After adjusting for confounding factors, Native American mothers were more likely to have retained placenta (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.35-1.81), whereas Black (OR, 0.92; 95% CI, 0.88-0.97) and Hispanic mothers (OR, 0.84; 95% CI, 0.80-0.89) were significantly less likely to have retained placenta than White mothers. Furthermore, those who delivered with a retained placenta were significantly associated with higher in-hospital mortality, a longer duration of stay, and hospitalization expenditures, which were disproportionately varied by maternal race and ethnicity.

CONCLUSIONS

The incidence of retained placenta among people undergoing vaginal delivery is exhibiting an upward trend over time, with notable variations observed across different ethnic groups by unclear mechanisms. The ramifications of these findings have the potential to impact the clinical management of maternal health care and the creation of health policies, specifically in relation to the Native American birth population.

Manual removal of the placenta and postpartum hemorrhage: A multicenter retrospective study

AIM

In postpartum women, retained placenta is diagnosed in the absence of signs of placental separation and expulsion, and requires manual removal of the placenta (MROP). MROP may lead to massive hemorrhage, hemodynamic instability, and the need for emergency interventions including blood transfusion, interventional radiology, and hysterectomy. In this study, we aimed to identify the risk factors for retained placenta requiring MROP after vaginal delivery and postpartum hemorrhage (PPH) following MROP.

METHODS

A multicenter retrospective study was performed using data from women who delivered at term between 2010 and 2018 at 13 facilities in Japan. Of 36 454 eligible women, 112 women who required MROP were identified. Multivariate logistic regression analyses were conducted to evaluate the risk factors for retained placenta and PPH following MROP.

RESULTS

A history of abortion, assisted reproductive technology (ART), instrumental delivery, and delivery of small-for-gestational-age infant were independent risk factors for MROP (adjusted odds ratios [95% confidence intervals]: 1.93 [1.28-2.92], 8.41 [5.43-13.05], 1.80 [1.14-2.82], and 4.32 [1.97-9.48], respectively). ART was identified as an independent risk factor for PPH (adjusted odds ratio [95% confidence interval]: 6.67 [2.42-18.36]) in patients who underwent MROP.

CONCLUSION

ART pregnancies significantly increased the risk of retained placenta requiring MROP and PPH. Our results suggest that clinicians need consider patient transfer to a higher-level facility and preparation of sufficient blood products before initiating MROP in cases of ART pregnancies. Our study may assist in identifying high-risk women for PPH before MROP and in guiding treatment decisions, especially in facilities without a blood bank.

Umbilical vein injection for management of retained placenta

BACKGROUND

Retained placenta is a common complication of pregnancy affecting 1% to 6% of all births. If a retained placenta is left untreated, spontaneous delivery of the placenta may occur, but there is a high risk of bleeding and infection. Manual removal of the placenta (MROP) in an operating theatre under anaesthetic is the usual treatment, but is invasive and may have complications. An effective non-surgical alternative for retained placenta would potentially reduce the physical and psychological trauma of the procedure, and costs. It could also be lifesaving by providing a therapy for settings without easy access to modern operating theatres or anaesthetics. Injection of uterotonics into the uterus via the umbilical vein and placenta is an attractive low-cost option for this. This is an update of a review last published in 2011.

OBJECTIVES

To assess the use of umbilical vein injection (UVI) of saline solution with or without uterotonics compared to either expectant management or with an alternative solution or other uterotonic agent for retained placenta.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (14 June 2020), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing UVI of saline or other fluids (with or without uterotonics), either with expectant management or with an alternative solution or other uterotonic agent, in the management of retained placenta. We considered quasi-randomised, cluster-randomised, and trials reported only in abstract form.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. We assessed the certainty of the evidence using the GRADE approach. We calculated pooled risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs), and presented results using 'Summary of findings' tables.

MAIN RESULTS

We included 24 trials (n = 2348). All included trials were RCTs, one was quasi-randomised, and none were cluster-randomised. Risk of bias was variable across the included studies. We assessed certainty of evidence for four comparisons: saline versus expectant management, oxytocin versus expectant management, oxytocin versus saline, and oxytocin versus plasma expander. Evidence was moderate to very-low certainty and downgraded for risk of bias of included studies, imprecision, and inconsistency of effect estimates. Saline solution versus expectant management There is probably little or no difference in the incidence of MROP between saline and expectant management (RR 0.93, 95% CI 0.80 to 1.10; 5 studies, n = 445; moderate-certainty evidence). Evidence for the following remaining primary outcomes was very-low certainty: severe postpartum haemorrhage 1000 mL or greater, blood transfusion, and infection. There were no events reported for maternal mortality or postpartum anaemia (24 to 48 hours postnatal). No studies reported addition of therapeutic uterotonics. Oxytocin solution versus expectant management UVI of oxytocin solution might slightly reduce in the need for manual removal compared with expectant management (mean RR 0.73, 95% CI 0.56 to 0.95; 7 studies, n = 546; low-certainty evidence). There may be little to no difference between the incidence of blood transfusion between groups (RR 0.81, 95% CI 0.47 to 1.38; 4 studies, n = 339; low-certainty evidence). There were no maternal deaths reported (2 studies, n = 93). Evidence for severe postpartum haemorrhage of 1000 mL or greater, additional uterotonics, and infection was very-low certainty. There were no events for postpartum anaemia (24 to 48 hours postnatal). Oxytocin solution versus saline solution UVI of oxytocin solution may reduce the use of MROP compared with saline solution, but there was high heterogeneity (RR 0.82, 95% CI 0.69 to 0.97; 14 studies, n = 1370; I² = 54%; low-certainty evidence). There were no differences between subgroups according to risk of bias or oxytocin dose for the outcome MROP. There may be little to no difference between groups in severe postpartum haemorrhage of 1000 mL or greater, blood transfusion, use of additional therapeutic uterotonics, and antibiotic use. There were no events for postpartum anaemia (24 to 48 hours postnatal) (very low-certainty evidence) and there was only one event for maternal mortality (low-certainty evidence). Oxytocin solution versus plasma expander One small study reported UVI of oxytocin compared with plasma expander (n = 109). The evidence was very unclear about any effect on MROP or blood transfusion between the two groups (very low-certainty evidence). No other primary outcomes were reported. For other comparisons there were little to no differences for most outcomes examined. However, there was some evidence to suggest that there may be a reduction in MROP with prostaglandins in comparison to oxytocin (4 studies, n = 173) and ergometrine (1 study, n = 52), although further large-scale studies are needed to confirm these findings.

AUTHORS' CONCLUSIONS

UVI of oxytocin solution is an inexpensive and simple intervention that can be performed when placental delivery is delayed. This review identified low-certainty evidence that oxytocin solution may slightly reduce the need for manual removal. However, there are little or no differences for other outcomes. Small studies examining injection of prostaglandin (such as dissolved misoprostol) into the umbilical vein show promise and deserve to be studied further.

Pharmacologic intervention for the management of retained placenta: a systematic review and meta-analysis of randomized trials

BACKGROUND

Retained placenta affects 2% to 3.3% of all vaginal deliveries and is one of the leading causes of postpartum hemorrhage worldwide. Despite the prevalence of this condition, there is limited guidance on its management.

OBJECTIVE

A systematic review and meta-analysis were performed to evaluate the efficacy of pharmacologic interventions for the management of retained placenta.

STUDY DESIGN

PubMed, ClinicalTrials.gov, Cochrane Library, Web of Science, and Scopus were searched for full-text publications in English. Search terms included "retained placenta" AND "treatment" OR "therapy" OR "disease management" OR "Pitocin" OR "misoprostol" OR "Cytotec" OR "dinoprostone" OR "nitroglycerin" OR "carbetocin" OR "ergotamine," with no restriction on publication dates. Only randomized controlled trials were included. The primary outcome was the need for manual extraction of the placenta or dilation and curettage. Reviewers evaluated the quality of included articles using the Cochrane Collaboration's tool for assessing the risk of bias. Pooled risk ratios were estimated based on random- and fixed-effects analyses. Interstudy heterogeneity was considered when I²≥50%.

RESULTS

The literature search identified 29 randomized controlled trials that met the inclusion criteria (2682 subjects). The most commonly used agent across the studies was oxytocin administered via umbilical vein injection; there was high heterogeneity among these studies (I²=62%). Oxytocin was inferior to carbetocin (risk ratio, 1.61; 95% confidence interval, 1.03-2.52) and prostaglandins (risk ratio, 2.63; 95% confidence interval, 1.18-5.86) for the primary outcome. For oxytocin, prostaglandin agents, and nitroglycerin, there was a trend toward favoring the study drug for the primary outcome compared with control or placebo. Compared with placebo or control, estimated blood loss was lower if pharmacologic interventions were administered, with a mean difference of 121.5 mL (95% confidence interval, -185.7 to -52.3). There was no difference in postpartum hemorrhage or the need for blood transfusion between pharmacologic interventions and placebo or control.

CONCLUSION

Pooled estimates for oxytocin via umbilical vein injection, prostaglandin agents, and nitroglycerin performed favorably compared with placebo or control for the management of retained placenta. Carbetocin and prostaglandin agents were superior to oxytocin in reducing the need for manual extraction or dilation and curettage.

Systematic review of prostaglandin analogues for retained placenta

BACKGROUND

Medical management of retained placenta could be a safe alternative to manual removal.

OBJECTIVE

To evaluate the efficacy of prostaglandin analogues for retained placenta.

SEARCH STRATEGY

MEDLINE, EMBASE, CENTRAL, ICTRP, LILACS, and OpenSIGLE were searched without language restrictions from inception to January 31, 2017, by combining terms for retained placenta and prostaglandin analogues.

SELECTION CRITERIA

Randomized controlled trials comparing prostaglandin analogues with any other intervention.

DATA COLLECTION AND ANALYSIS

Trials were independently assessed for inclusion, data extraction, and risk of bias. Data were extracted for meta-analyses. GRADE was used to evaluate the quality of data.

MAIN RESULTS

Seven randomized controlled trials (851 patients) were included. Prostaglandins did not increase the placenta expulsion rate (relative risk [RR] 1.40, 95% confidence interval [CI] 0.83-2.36) or decrease maternal transfusion (RR 0.72, 95% CI 0.43-1.22). In comparison with oxytocin, prostaglandins did not modify the expulsion rate (RR 1.26, 95% CI 0.90-1.78), maternal transfusion (RR 1.05, 95% CI 0.27-4.09), or time for delivery of placenta (mean difference -1.56 minutes, 95% CI, -9.25-6.13). Three trials comparing prostaglandins with oxytocin agonists, ergometrine, and manual removal reported similar results.

CONCLUSIONS

Prostaglandin analogues do not offer an effective alternative for management of retained placenta.

The inherited risk of retained placenta: a population based cohort study

OBJECTIVE

To investigate whether retained placenta in the first generation is associated with an increased risk of retained placenta in the second generation.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

Using linked generational data from the Swedish Medical Birth Register 1973-2012, we identified 494 000 second-generation births with information on the birth of the mother (first-generation index birth). For 292 897 of these births there was information also on the birth of the father.

METHODS

Risk of retained placenta in the second generation was calculated as adjusted odds ratios (aOR) by unconditional logistic regression with 95% confidence intervals (95% CI) according to whether retained placenta occurred in a first generation birth or not.

MAIN OUTCOME

Retained placenta in the second generation.

RESULTS

The risk of retained placenta in a second-generation birth was increased if retained placenta had occurred at the mother's own birth (aOR 1.66, 95% CI 1.52-1.82), at the birth of one of her siblings (aOR 1.58, 95% CI 1.43-1.76) or both (aOR 2.75, 95% CI 2.18-3.46). The risk was slightly increased if retained placenta had occurred at the birth of the father (aOR 1.23, 95% CI 1.07-1.41). For preterm births in both generations, the risk of retained placenta in the second generation was increased six-fold if retained placenta had occurred at the mother's birth (OR 6.55, 95% CI 2.68-16.02).

CONCLUSION

There is an intergenerational recurrence of retained placenta on the maternal and most likely also on the paternal side. The recurrence risk seems strongest in preterm pregnancies.

TWEETABLE ABSTRACT

A population-based cohort study suggests that there is an intergenerational recurrence of retained placenta.

Different routes and forms of uterotonics for treatment of retained placenta: a randomized clinical trial

OBJECTIVES

To compare between three different uterotonics (oxytocin, carbetocin and misoprostol) given via three different routes (intraumbilical, intravenous and sublingual, respectively) in reducing the need for manual removal of placenta (MROP).

METHODS

A randomized trial for cases with retained placenta 30 min following vaginal delivery. They received intraumbilical oxytocin, intravenous carbetocin or sublingual misoprostol. Main outcome measures were delivery of the placenta within 30 min following drug administration, and need for MROP. Secondary outcome measures were injection to placental delivery time, post-delivery hemoglobin, need for blood transfusion or additional uterotonics.

RESULTS

The overall success rate was 66.7% (64/96), 71.3% (67/94) and 63.7% (58/91) for oxytocin, carbetocin and misoprostol groups, respectively (p > 0.05). When time needed to achieve placental delivery considered, a significant difference was observed with the shortest time for carbetocin (16.61 ± 3.76 min), then oxytocin (18.28 ± 3.34 min) and lastly misoprostol (23.00 ± 3.38 min) (p <0.001). Again, carbetocin group needed less additional uterotonics to achieve adequate uterine contractions (p <0.001).

CONCLUSIONS

Although we aimed to exploit the advantage of certain drug over another, all seemed to have close efficacy but it would be important that further research should highlight availability, cost, ease of administration and storage requirements to determine which agent would best be used in this clinical scenario.