Risk of retained placenta in women previously delivered by caesarean section: a population-based cohort study

Association between first-trimester ultrasound imaging of eccentric implantation and retained placenta

OBJECTIVES

To evaluate first-trimester ultrasound imaging of eccentric implantation in predicting the probability of retained placenta.

METHODS

A total of 61 cases with gestational sac eccentrically implanted in first-trimester ultrasound imaging was selected. Demographic and obstetric data were collected through data extraction of the electronic medical record at the time of delivery admission. Baseline characteristics (including age, gestational age of first-trimester ultrasound, size of gestational sac, gestational age of delivery), delivery outcomes (mode of delivery, retained placenta or placental fragments, blood loss, postpartum hemorrhage and postpartum ultrasound imaging) were collected and analyzed.

RESULTS

The risk difference for a woman with eccentric implantation to have a retained placenta was -0.18 (95% CI -0.28 to -0.08, p = 0.000) and the incidence of retained placenta in the study group was higher than in the control group (18% vs. 0%, p = 0.006). First-trimester ultrasound imaging of eccentric implantation was also found to be an independent risk factor for the incidence of inhomogeneous mass in postpartum ultrasound imaging (27.9% vs. 10.8%, adjusted OR 0.19, 95% CI 0.05 to 0.79, p = 0.012). Though 2 cases in the study group suffered postpartum hemorrhage, the risk difference for a woman with eccentric implantation to suffer postpartum hemorrhage was -0.03 (95% CI -0.08 to -0.01, not significant) and eccentric implantation did not increase postpartum hemorrhage rates (3.3% vs. 0%, not significant).

CONCLUSIONS

First-trimester ultrasound imaging of eccentric implantation was associated with an increased risk of retained placenta and inhomogeneous mass in postpartum ultrasound imaging.

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.

The association between history of retained placenta and success rate of misoprostol treatment for early pregnancy failure

BACKGROUND

To date, the association between retained placenta and treatment success rate of misoprostol for early pregnancy failure has yet to be evaluated. The aim of this study was to evaluate this association and further investigated the connection between medical, clinical and sonographic parameters and treatment success.

METHODS

We conducted a retrospective cohort study of women with early pregnancy failure treated with misoprostol from 2006 to 2021. The success rate of misoprostol treatment was compared between patients with history of retained placenta including women who underwent manual lysis of the placenta following delivery or patients who were found to have retained products of conception during their post-partum period (study group) and patients without such history (controls). Demographic, clinical, and sonographic characteristics as well as treatment outcomes were compared between the groups.

RESULTS

A total of 271 women were included in the study (34 women in the study group compared to 237 women in the control group). Two-hundred and thirty-three women (86.0%) presented with missed abortion, and 38 (14.0%) with blighted ovum. Success rates of misoprostol treatment were 61.8% and 78.5% for the study and control groups, respectively (p = 0.032). Univariate analysis performed comparing successful vs. failed misoprostol treatment showed advanced age, gravidity, parity and gestational sac size (mm) on TVUS were associated with higher misoprostol treatment failure rate. Following a multivariate logistic regression model these variables did not reach statistical significance.

CONCLUSION

Women who have an event of retained placenta following childbirth appear to have decreased success rate of treatment with misoprostol for early pregnancy failure. Larger studies are needed to confirm this finding.

Frequency of Caesarean Section Classified by Robson's Ten Group Classification System: A Scoping Review

The prevalence of caesarean section (CS) is rising rapidly. However, it should be carried out only under valid obstetric indications due to the various complications associated with it. Therefore, to record CS incidences, Robson's Ten Group Classification System (TGCS) was implemented. This review focuses on the prevalence of CS rates found in various studies and identifies the clinically important groups that were most involved in CS deliveries. Preferred Reporting Items for Systematic Review and Meta-Analysis Extension for Scoping Review (PRISMA-ScR) guidelines were followed in this review. "Caesarean delivery" OR "Robson's Ten Group" OR "Classification System" were keywords used to search literature. Twenty-one studies were included in this review based on eligibility criteria. We concluded that group 5 was the major contributing factor for the increase in CS rates followed by group 10, group 4, group 2, and group 1. Previous CS was the most common factor responsible for increasing CS rates. We emphasize that Robson's TGCS is an essential parameter for recording CS rates and is simple to use for CS rate comparison.

Risk factors and recurrence of cause-specific postpartum hemorrhage: A population-based study

OBJECTIVE

To explore risk profiles of the different types of postpartum hemorrhage (PPH >500ml or severe PPH >1500ml) and their recurrence risks in a subsequent delivery.

METHODS

With data from The Medical Birth Registry of Norway and Statistics Norway we performed a population-based cohort study including all singleton deliveries in Norway from 1967-2017. Multilevel logistic regression was used to calculate odds ratio (OR), with 95% confidence interval (CI), with different PPH types (PPH >500ml or PPH >1500ml (severe PPH) combined with retained placenta, uterine atony, obstetric trauma, dystocia, or undefined cause) as outcomes.

RESULT

We identified 277 746 PPH cases of a total of 3 003 025 births (9.3%) from 1967 to 2017. Retained placenta (and/or membranes) was most often registered as severe PPH (29.3%). Maternal, fetal, and obstetric characteristics showed different associations with the PPH types. Male sex of the neonate was associated with reduced risk of PPH. This effect was strongest on PPH due to retained placenta (adjusted OR, (aOR): 0.80, 95% CI 0.78-0.82), atony (aOR 0.92, 95% CI: 0.90-0.93) and PPH with undefined cause (aOR 0.96, 95% CI: 0.95-0.97). Previous cesarean section showed a strong association with PPH due to dystocia (aOR of 13.2, 95% CI: 12.5-13.9). Recurrence risks were highest for the same type: PPH associated with dystocia (aOR: 6.8, 95% CI: 6.3-7.4), retained placenta and/or membranes (aOR: 5.9, 95% CI: 5.5-6.4), atony (aOR: 4.0, 95% CI: 3.8-4.2), obstetric trauma (aOR: 3.9, 95% CI: 3.5-4.3) and PPH of undefined cause (aOR: 2.2, 95% CI: 2.1-2.3).

CONCLUSION

Maternal, fetal and obstetric characteristics had differential effects on types of PPH. Recurrence differed considerably between PPH types. Retained placenta was most frequently registered with severe PPH, and showed strongest effect of sex; delivery of a boy was associated with lower risk of PPH. Previous cesarean increased the risk of PPH due to dystocia.

Cesarean Audit Using Robson Classification at a Tertiary Care Center in Bihar: A Retrospective Study

Background

Since 1985, the international healthcare community has considered the ideal rate for cesarean section (CS) to be between 10% and 15%.However, CS has been increasing both in developed and developing countries. The aim of the present study was to audit CS using Robson’s Ten Group Classification System (TGCS).

Methodology

This retrospective, hospital record-based study was conducted over a period of three years from April 1, 2016, to March 31, 2019, in the Department of Obstetrics and Gynecology at Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India. Data of patients who delivered by CS during this period were recorded and categorized in the 10 groups of TGCS. The size of each group, CS rate, and contribution of each group toward overall CS were calculated. Indications of CS in each group were analyzed, and strategies were planned to optimize the use of CS. The Chi-square test was used to analyse the statistical significance of the differences in the number of CS between the different Robson's groups.

Results

The total number of deliveries was 2,128 during the study period, of which CS was performed in 812 deliveries, with a CS rate of 38.16% in our institute. Robson’s group 5 (34.97%) was the major contributor to the overall CS rate, followed by group 2 (26.35%), group 1 (15.51%), and group 10 (7.14%). The incidence of primary CS (61.82%) was more than repeat CS (38.17%). Previous CS, fetal distress, failed induction, arrest of labor, and malpresentation were the main indications for CS.

Conclusions

Robson’s TGCS serves as an important tool for auditing CS. Indications of CS among major contributors and primary group should be analyzed regularly and uniform and standard protocols should be used. Standardization of indications for CS, regular audits, and definite protocols will help in reducing the CS rate in our hospital.

Distribution of cesarean delivery by Robson classification and predictors of postspinal anesthesia hypotension in Windhoek referral hospitals: A cross-sectional study

Background

There are concerns that high cesarean section (CS) rates are driven by nonmedical indications and unmitigated maternal hypotension following spinal anesthesia (SA) has materno fetal effects.

Aims

Our objective was to investigate CS rates using Robson classification, identify patient groups for focused intervention as well as assess the incidence and predictors of maternal hypotension following SA for cesarean delivery.

Subjects and Methods

A cross sectional design was employed over 3 months (February-April, 2019). Data about total deliveries (vaginal and operative) were obtained from the hospital medical records. For parturients who had CS, variables which covered maternal characteristics, conduct of anesthesia, and the index pregnancy according to Robson classification system were entered into a proforma designed for the study.

Results

The total deliveries were 3031, of which 556 were CSs, giving a CS rate of 18.3%. Twenty one nonconsenting parturients were excluded, so 535 responded. Robson groups 5, 10, and 1 combined contributed 75% [401/535] to the overall CS. Two or more previous CS, 29.7% [159/535], was the main indication for performing CS, followed by maternal request 12.9% [69/535]. The incidence of maternal hypotension was 62.6% (293/468); the independent predictors were elective CS and having comorbidities.

Conclusion

We found a low CS rate and Robson groups 5, 10, and 1 were the major contributors - previous CS (≥2) and maternal request were the predominant indications for performing CS. The independent predictors of SA induced hypotension were presence of comorbidities and elective CS.

Correlation Between Previous Caesarean Section and Adverse Maternal Outcomes Accordingly With Robson Classification: Systematic Review and Meta-Analysis

Background: The increasing rates of Caesarean section (CS) beyond the WHO standards (10–15%) pose a significant global health concern.

Objective: Systematic review and meta-analysis to identify an association between CS history and maternal adverse outcomes for the subsequent pregnancy and delivery among women classified in Robson classification (RC).

Search Strategy: PubMed/Medline, EbscoHost, ProQuest, Embase, Web of Science, BIOSIS, MEDLINE, and Russian Science Citation Index databases were searched from 2008 to 2018.

Selection Criteria: Based on Robson classification, studies reporting one or more of the 14 adverse maternal outcomes were considered eligible for this review.

Data Collection: Study design data, interventions used, CS history, and adverse maternal outcomes were extracted.

Main Results: From 4,084 studies, 28 (n = 1,524,695 women) met the inclusion criteria. RC group 5 showed the highest proportion among deliveries followed by RC10, RC7, and RC8 (67.71, 32.27, 0.02, and 0.001%). Among adverse maternal outcomes, hysterectomy had the highest association after preterm delivery OR = 3.39 (95% CI 1.56–7.36), followed by Severe Maternal Outcomes OR = 2.95 (95% CI 1.00–8.67). We identified over one and a half million pregnant women, of whom the majority were found to belong to RC group 5.

Conclusions: Previous CS was observed to be associated with adverse maternal outcomes for the subsequent pregnancies. CS rates need to be monitored given the prospective risks which may occur for maternal and child health in subsequent births.

Delivery Mode after Ileal Pouch-Anal Anastomosis among Pregnant Women with Ulcerative Colitis

Objectives:

The appropriate and recommended delivery mode after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) has not been sufficiently evaluated. This study was designed to compare the delivery outcomes associated with cesarean section (CS) and vaginal delivery (VD) after IPAA.

Methods:

We conducted a questionnaire-based survey of female patients who underwent IPAA for UC between July 1987 and May 2018. Additionally, we reviewed clinical data and collected information regarding pouch function and postpartum complications.

Results:

In total, 45 patients had 68 deliveries, including 64 CS deliveries and four VDs. Fecal incontinence worsened in seven patients, including six CS patients and one VD patient. The Wexner scores of these patients before and after delivery were 5.4 ± 0.4 and 14.8 ± 1.0, respectively (p = 0.005). Four patients in the CS group and one in the VD group (p = 0.32) had increased stool frequency. Bowel obstructions developed during 11/64 (17.2%) deliveries, and one patient required surgical intervention. One patient with four VDs (three before IPAA and one after IPAA) developed vaginal fistula 5 months after the final VD. Information on episiotomies could not be obtained.

Conclusions:

Pouch function can decline even after CS. Notably, bowel obstruction can develop after CS. However, we cannot recommend a particular delivery method after IPAA. Further analyses to elucidate the relationship between CS and postoperative complications or vaginal fistula and episiotomy in VDs should be conducted.

Postpartum ovarian vein thrombophlebitis presenting as vaginal bleeding: A case report

RATIONALE

Postpartum ovarian vein thrombophlebitis (POVT) is a rare condition, and it can lead to severe complications and mortality. Here we report a patient who presented with vaginal bleeding and the diagnosis of POVT was confirmed by imaging.

PATIENT CONCERNS

A 38-year-old postpartum woman without remarkable medical history presented with vaginal bleeding and lower abdominal pain.

DIAGNOSES

The diagnosis was confirmed by computed tomography scan marked by a thrombus mass involving the right ovarian vein and inferior vena cava.

INTERVENTIONS

The patient was treated with intravenous antibiotics and low-molecular-weight heparin.

OUTCOMES

The patient recovered smoothly without complications.

LESSONS

We should pay high attention to the recognition and management of POVT to prevent morbidity and mortality.

Risk factors for third stage placental complications among primigravid women

INTRODUCTION

Third stage placental complications (TSPC) including partially or complete retained placenta, are a common obstetric complication. Previous studies have underlined risk factors for TSPC in heterogenous populations of women, whereas data regarding primigravid term women are scarce. We aimed to identify the factors associated with TSPC in this subset of parturients.

METHODS

A retrospective cohort study including all primigravid women who delivered vaginally a term, live-singleton neonate between 2011 and 2019. Women who underwent revision of the uterine cavity due to TSPC were compared with those who did not. Univariate and multivariate regression analyses were performed in order to identify the risk factors for TSPC.

RESULTS

Overall, 16,867 deliveries met the study inclusion criteria. Of those, 1097 (6.5%) deliveries were complicated by TSPC. Women with TSPC were older (p < 0.001) and with a higher proportion of lateral and fundal placental location (p < 0.001). In a multivariate regression analysis, the following factors were positively independently associated with TSPC: maternal age (aOR [95% CI] 1.26 (1.17-1.36), p < 0.001), the use of assisted reproduction technologies (aOR [95% CI] 1.26 (1.06-1.49), p = 0.007), preeclampsia (aOR [95% CI] 3.39 (1.89-6.10), p < 0.001), thrombocytopenia (aOR [95% CI] 1.83 (1.34-2.48), p < 0.001), oxytocin administration (aOR [95% CI] 1.29 (1.12-1.48), p < 0.001) and longer second stage duration (aOR [95% CI] 1.03 (1.003-1.05), p = 0.02). Fetal male gender was negatively associated with TSPC (aOR [95% CI] 0.80 (0.70-0.92), p = 0.002).

DISCUSSION

We have identified multiple independent risk factors for TSPC among primigravid women. This information can aid in patient counseling and delivery management in these subset of parturients.

Placental location and risk of retained placenta in women with a previous cesarean section: A population-based cohort study

INTRODUCTION

Some studies have shown that women with a previous cesarean section, compared with women with a previous vaginal delivery, have an increased risk of retained placenta during a subsequent vaginal delivery. It is unknown whether this is mediated by anterior placental location, when the placenta might cover the uterine scar. The aim of this study was to evaluate whether the increased risk of retained placenta in women with a previous cesarean section is mediated by anterior placental location.

MATERIAL AND METHODS

This is a population-based cohort study, with data from the regional population-based Stockholm-Gotland Obstetric Cohort, Sweden, from 2008 to 2014. The overall study population included 49 598 women with a vaginal second delivery, where adequate information about placental location from the second-trimester ultrasound scan was available. For the main analysis, including the 3921 women with a previous cesarean section, we calculated the relative risk of retained placenta in women with an anterior placental location, using women with non-anterior placental locations as reference. Relative risks were calculated as odds ratios (OR) with 95% CI. In a second model, adjustments were made for maternal age, height, country of birth, smoking in early pregnancy, infant sex, and in vitro fertilization.

RESULTS

In the overall study population, the rate of retained placenta at the second delivery was 2.0%. The proportion of women with a retained placenta was higher among women with a previous cesarean compared with those with a previous vaginal delivery (3.4% vs 1.9%; P < .0001). In the main analysis, including women with a previous cesarean section, the risk for retained placenta was not increased with anterior compared with non-anterior placental location (OR 0.84, 95% CI 0.60-1.20). Adjustments did not affect the estimates in a significant way.

CONCLUSIONS

The increased risk of retained placenta in women with a previous cesarean section is not mediated by anterior placental location.

Risk factors, early and late postpartum complications of retained placenta: A case control study

OBJECTIVES

To identify risk factors and complications associated with 3^rd stage of labor removal of placental fragments (3^rd SRPF) by manual uterine revision under a strict protocol.

STUDY DESIGN

Ten years retrospective register-based cohort study of vaginal deliveries. Women with 3^rd SRPF n = 3297 (exposed) and those without n = 97,888 (non exposed) were compared.

MAIN OUTCOMES MEASURES

(1) risk factors for 3^rd SRPF aOR (95%CI) (2) early (2a) and late (2b) maternal complications.

RESULTS

(1) Risk factors for 3^rd SRPF procedure were assisted reproductive technologies 2.20 (1.73-2.34), preterm delivery 2.53 (2.21-2.88), preeclampsia 1.66 (1.25-2.21) Multiple previous early pregnancy loss (>3) 1.40(1.19-1.66), VBAC 1.26(1.13-1.47) and epidural analgesia 1.56 (1.46-1.69). (2a) Early complications: puerperal fever 1.1% vs 0.3%, blood transfusion 9.0% vs. 0.5%, prolonged maternal hospitalization 21.0% vs. 11.4%, all P < 0.0001. Puerperal readmission was 0.819% in the 3^rd SRPF vs. 0.315% the control group, P < 0.0001. (2b) Late complications: retained placenta and hysteroscopy / D&C rates were significantly higher among the 3^rd SRPF vs. controls: 40.7% vs. 7.1%, 14.8% vs. 3.6% and 48.1% vs. 18.2%, respectively, all P < 0.0001.

CONCLUSION

Uterine revision for 3^rd SPRF is associated with significant early and late maternal morbidity; should be considered discriminative of a population at risk and postpartum health care planning, beyond being a therapeutic intervention.

Analysis of caesarean sections using Robson 10-group classification system in a university hospital in eastern Ethiopia: a cross-sectional study

OBJECTIVE

To analyse caesarean section (CS) using Robson 10-group classification system in an Ethiopian university hospital.

DESIGN

Cross-sectional study.

SETTING

A university hospital in eastern, Ethiopia.

PARTICIPANTS

980 women who underwent CS from January 2016 to April 2017.

MAIN OUTCOME

Robson groups (1-10-based on gestational age, fetal presentation, number of fetus, onset of labour and history of CS) and indications for CS.

RESULTS

Robson group 3 (multiparous women with single cephalic full-term pregnancy in spontaneous labour with no history of CS), group 5 (multiparous women with single cephalic full-term pregnancy with history of CS) and group 1 (single cephalic nulliparous women full-term pregnancy in spontaneous labour) were the major contributors to the overall CS at 21.4%, 21.1% and 19.3%, respectively. The three major indications for CS were fetal compromise (mainly fetal distress), obstructed labour (mainly cephalopelvic disproportion) and previous CS.

CONCLUSION

Robson groups 3, 5 and 1 were the major contributors to the overall CS rate. Fetal compromise, obstructed labour and previous CS were the underlying indications for performing CS. Further study is required to assess the appropriateness of the indications and to reduce CS among the low-risk groups (groups 1 and 3).

The risk of placenta accreta following primary cesarean delivery

OBJECTIVE

To (a) evaluate the risk for placenta accreta following primary cesarean section (CS), in regard to the stage of labor, the cesarean section was taken (elective prelabor vs. unplanned during labor); and (b) investigate whether the association between placenta accreta and maternal and neonatal complications is modified by the type of the primary CS.

STUDY DESIGN

In a population-based retrospective cohort study, we included all singleton deliveries occurred in Soroka University Medical Center between 1991 and 2015, of women who had a history of a single CS. The deliveries were divided into three groups according to the delivery stage the primary CS was carried out: 'Unplanned 1' (first stage-up to 10 cm), 'Unplanned 2' (second stage-10 cm) and 'Elective' prelabor CS. We assessed the association between the study group and placenta accreta using logistic generalized estimation equation (GEE) models. We additionally assessed maternal and neonatal complications associated with placenta accreta among women who had elective and unplanned CS separately.

RESULTS

We included 22,036 deliveries to 13,727 women with a history of one CS, of which 0.9% (n = 207) had placenta accreta in the following pregnancies: 12% (n = 25) in the 'Unplanned 1' group, 7.2% (n = 15) in the ' Unplanned 2' group and 80.8% (n = 167) in the 'elective' group. We found no difference in the risk for subsequent placenta accreta between the groups. In a stratified analysis by the timing of the primary cesarean delivery, the risk for maternal complications, associated with placenta accreta, was more pronounced among women who had an unplanned CS (OR 27.96, P < 0.01) compared to women who had an elective cesarean delivery (OR 13.72, P < 0.01).

CONCLUSIONS

The stage in which CS is performed has no influence on the risk for placenta accreta in the following pregnancies, women who had an unplanned CS are in a higher risk for placenta accrete-associated maternal complications. This should be taken into consideration while counselling women about their risk while considering trial of labor after cesarean section.

Failed manual removal of the placenta after vaginal delivery

PURPOSE

A retained placenta after vaginal delivery where manual removal of placenta fails is a clinical challenge. We present six cases that illustrate the heterogeneity of the condition and discuss the etiology and terminology as well as the clinical management.

METHODS

Members of the European Working group on Abnormally Invasive Placenta (EW-AIP) were invited to report all recent cases of retained placenta that were not antenatally suspected to be abnormally adherent or invasive, but could not be removed manually despite several attempts.

RESULTS

The six cases from Denmark, The Netherlands and the UK provide examples of various treatment strategies such as ultrasound-guided vaginal removal, removal of the placenta through a hysterotomy and just leaving the placenta in situ. The placentas were all retained, but it was only possible to diagnose abnormal invasion in the one case, which had a histopathological diagnosis of increta. Based on these cases we present a flow chart to aid clinical management for future cases.

CONCLUSION

We need properly defined stringent terminology for the different types of retained placenta, as well as improved tools to predict and diagnose both abnormally invasive and abnormally adherent placenta. Clinicians need to be aware of the options available to them when confronted by the rare case of a retained placenta that cannot be removed manually in a hemodynamically stable patient.

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.

Placental location, postpartum hemorrhage and retained placenta in women with a previous cesarean section delivery: a prospective cohort study

OBJECTIVE

Women previously giving birth with cesarean section have an increased risk of postpartum hemorrhage (PPH) and retained placenta. The objective of this study was to determine if anterior placental location increased the risk of PPH and retained placenta in such women.

MATERIALS AND METHODS

We performed a prospective cohort study on 400 women with cesarean section delivery in a previous pregnancy. Ultrasound examinations were performed at gestational week 28-30, and placental location, myometrial thickness, and three-dimensional vascularization index (VI) were recorded. Data on maternal age, parity, BMI, smoking, gestational week at delivery, induction, delivery mode, oxytocin, preeclampsia, PPH, retained placenta, and birth weight were obtained for all women. Outcome measures were PPH (≥1,000 mL) and retained placenta.

RESULTS

The overall incidence of PPH was 11.0% and of retained placenta 3.5%. Twenty-three women (11.8%) with anterior placenta had PPH compared to 12 (6.9%) with posterior or fundal locations. The odds ratio was 1.94, but it did not reach statistical significance. There was no significant risk increase for retained placenta in women with anterior placentae. Seven of eight women with placenta previa had PPH, and four had retained placenta.

CONCLUSIONS

The overall risk of PPH and retained placenta was high for women with previous cesarean section. Anterior location of the placenta in such women tended to impose an increased risk for PPH but no risk increase of retained placenta. Placenta previa in women with previous cesarean section is associated with a high risk for PPH and retained placenta.

Underlying mechanisms of retained placenta: Evidence from a population based cohort study

OBJECTIVE

To determine risk factors for retained placenta, and to identify supporting epidemiologic evidence for the three previously-proposed mechanisms: (i) invasive placentation, (ii) placental hypo-perfusion, and (iii) inadequate uterine contractility.

DESIGN

A retrospective population-based cohort study.

SETTING AND POPULATION

Israeli population in the southern district.

METHODS

Data were analyzed from a tertiary hospital database, between 1989 and 2014, using univariate tests and generalized estimating equation (GEE) multivariable models.

MAIN OUTCOME MEASURES

Prevalence of retained placenta.

RESULTS

The study population included 205,522 vaginal deliveries of which 4.8% (n=9870) were complicated with retained placenta. Previous intra-uterine procedures and placenta-related pregnancy complications were found to be significant risk factors for retained placenta (history of cesarean section aOR=8.82, 95%CI 8.35-9.31; history of curettage aOR=12.80, 95%CI 10.57-15.50; pre-eclampsia aOR=1.25, 95%CI 1.14-1.38; delivery of a small for gestational age neonate aOR=1.08, 95%CI 1.01-1.16; stillbirth aOR=2.34, 95%CI 1.98-2.77). During labour, the risk for retained placenta was increased in presence of arrest of dilatation (aOR=2.03, 95%CI 1.08-3.82) or arrest of descent (aOR=1.55, 95%CI 1.22-1.96). Infections of the uterine cavity during labour were also found to be strongly associated with increased risk of retained placenta (endometritis aOR=2.21, 95%CI 1.64-2.97; chorioamnionitis aOR=3.35, 95% CI 2.78-4.04).

CONCLUSIONS

Supporting epidemiologic evidence were found for all three underlying mechanisms. In addition, there is evidence to suggest that intrauterine infection and inflammation may also be a possible pathology associated with retained placenta.

TWEETABLE ABSTRACT

Risk factors for retained placenta support previously proposed mechanisms in a large cohort study.

The Ten-Group Robson Classification: A Single Centre Approach Identifying Strategies to Optimise Caesarean Section Rates

Caesarean section (CS) rates have been increasing worldwide and have caused concerns. For meaningful comparisons to be made World Health Organization recommends the use of the Ten-Group Robson classification as the global standard for assessing CS rates. 2625 women who birthed over a 12-month period were analysed using this classification. Women with previous CS (group 5) comprised 10.9% of the overall 23.5% CS rate. Women with one previous CS who did not attempt VBAC contributed 5.3% of the overall 23.5% CS rate. Second largest contributor was singleton nulliparous women with cephalic presentation at term (5.1% of the total 23.5%). Induction of labour was associated with higher CS rate (groups 1 and 3) (24.5% versus 11.9% and 6.2% versus 2.6%, resp.). For postdates IOL we recommend a gatekeeper booking system to minimise these being performed <41 weeks. We suggest setting up dedicated VBAC clinic to support for women with one previous CS. Furthermore review of definition of failure to progress in labour not only may lower CS rates in groups 1 and 2a but also would reduce the size of group 5 in the future.

Is epidural analgesia during labor related to retained placenta?

OBJECTIVES

To explore the influence of epidural analgesia on the course of the third stage of labor and on the incidence of the complete retained placenta as well as retained parts of the placenta.

STUDY DESIGN

This is a population-based cohort study in a tertiary medical center. We collected data from all 4227 spontaneous singleton vaginal deliveries during 6 months and compared the incidence of retained placenta in deliveries with epidural analgesia with those without analgesia. Multivariable logistic regression was used to control for possible confounders.

RESULTS

More than two-thirds of the women (69.25%) used epidural analgesia during their delivery. A need for intervention due to placental disorder during the third stage of labor was noted in 4.2% of all deliveries. Epidural analgesia appeared to be significantly (P=0.028) related to placental disorders compared with no analgesia: 4.8% vs. 3%, respectively. Deliveries with manual interventions during the third stage, for either complete retained placenta or suspected retained parts of the placenta, were associated with the use of epidural analgesia (P=0.008), oxytocin (P=0.002) and older age at delivery (P=0.000), but when including all factors in a multivariable analysis, using a stepwise logistic regression, the factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and, marginally, older age.

CONCLUSIONS

Complete retained placenta and retained parts of the placenta share the same risk factors. Epidural analgesia does not directly influence the incidence of complete retained placenta or retained parts, though clinically linked through increased oxytocin use. The factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and older age.

Risk factors for retained placenta

OBJECTIVE

Retained placenta complicates 2-3% of vaginal deliveries and is a known cause of postpartum hemorrhage. Treatment includes manual or operative placental extraction, potentially increasing risks of hemorrhage, infections, and prolonged hospital stays. We sought to evaluate risk factors for retained placenta, defined as more than 30 minutes between the delivery of the fetus and placenta, in a large US obstetrical cohort.

STUDY DESIGN

We included singleton, vaginal deliveries ≥24 weeks (n = 91,291) from the Consortium of Safe Labor from 12 US institutions (2002-2008). Multivariable logistic regression analyses estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) for potential risk factors for retained placenta stratified by parity, adjusting for relevant confounding factors. Characteristics such as stillbirth, maternal age, race, and admission body mass index were examined.

RESULTS

Retained placenta complicated 1047 vaginal deliveries (1.12%). Regardless of parity, significant predictors of retained placenta included stillbirth (nulliparous adjusted OR, 5.67; 95% CI, 3.10-10.37; multiparous adjusted OR, 4.56; 95% CI, 2.08-9.94), maternal age ≥30 years, delivery at 24 0/7 to 27 6/7 compared with 34 weeks or later and delivery in a teaching hospital. In nulliparous women, additional risk factors were identified: longer first- or second-stage labor duration, whereas non-Hispanic black compared with non-Hispanic white race was found to be protective. Body mass index was not associated with an increased risk.

CONCLUSION

Multiple risk factors for retained placenta were identified, particularly the strong association with stillbirth. It is plausible that there could be something intrinsic about stillbirth that causes a retained placenta, or perhaps there are shared pathways of certain etiologies of stillbirth and a risk of retained placenta.

[Clinical and pharmacological procedures for the prevention of postpartum haemorrhage in the third stage of labor]

OBJECTIVES

To describe the clinical and pharmacological procedures for the prevention of Postpartum Haemorrhage (PPH).

MATERIALS AND METHODS

We searched the Medline and the Cochrane Library (1st December 2004 to 1st March 2014) and we checked the international guidelines.

RESULTS

Vaginal birth: only the use of uterotonics reduces the incidence of PPH. Oxytocin is the treatment of choice if it is readily available (grade A). Oxytocin can be used either after the shoulders expulsion or rapidly after the placental delivery (grade B). A dose of 5 or 10IU must be administrated IV over at least 1minute or directly by an intramuscular injection (professional agreement) except in women with documented cardiovascular disease in which the duration of the IV perfusion should be over at least 5minutes (professional agreement). Mechanical procedures have no significant impact on PPH. The decision to use a collector bag is left to the medical team (professional agreement). A systematic complementary oxytocin perfusion is not recommended (professional agreement). Caesarean delivery: There is no evidence to recommend a particular type of caesarean technique to prevent PPH (professional agreement) but a lower uterine section is recommended (grade B). All types of incision expansion may be used (professional agreement). A controlled cord traction is associated with lower blood losses than manual removal of the placenta (grade B). A dose of 5 or 10IU can be injected (IV) over 1minute, and over 5minutes in women with cardiovascular disease (professional agreement). Carbetocin reduces the incidence of PPH but there is presently no inferiority study comparing oxytocin and carbetocin so that oxytocin remains the gold standard therapy to prevent PPH in C-section (professional agreement).

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.