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BMJ Open Nov 2019To estimate the prevalence and incidence of placenta previa complicated by placenta accreta spectrum (PAS) and to examine the different criteria being used for the... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To estimate the prevalence and incidence of placenta previa complicated by placenta accreta spectrum (PAS) and to examine the different criteria being used for the diagnosis.
DESIGN
Systematic review and meta-analysis.
DATA SOURCES
PubMed, Google Scholar, ClinicalTrials.gov and MEDLINE were searched between August 1982 and September 2018.
ELIGIBILITY CRITERIA
Studies reporting on placenta previa complicated by PAS diagnosed in a defined obstetric population.
DATA EXTRACTION AND SYNTHESIS
Two independent reviewers performed the data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with difference agreed by consensus. The primary outcomes were overall prevalence of placenta previa, incidence of PAS according to the type of placenta previa and the reported clinical outcomes, including the number of peripartum hysterectomies and direct maternal mortality. The secondary outcomes included the criteria used for the prenatal ultrasound diagnosis of placenta previa and the criteria used to diagnose and grade PAS at birth.
RESULTS
A total of 258 articles were reviewed and 13 retrospective and 7 prospective studies were included in the analysis, which reported on 587 women with placenta previa and PAS. The meta-analysis indicated a significant (p<0.001) heterogeneity between study estimates for the prevalence of placenta previa, the prevalence of placenta previa with PAS and the incidence of PAS in the placenta previa cohort. The median prevalence of placenta previa was 0.56% (IQR 0.39-1.24) whereas the median prevalence of placenta previa with PAS was 0.07% (IQR 0.05-0.16). The incidence of PAS in women with a placenta previa was 11.10% (IQR 7.65-17.35).
CONCLUSIONS
The high heterogeneity in qualitative and diagnostic data between studies emphasises the need to implement standardised protocols for the diagnoses of both placenta previa and PAS, including the type of placenta previa and grade of villous invasiveness.
PROSPERO REGISTRATION NUMBER
CRD42017068589.
Topics: Female; Humans; Hysterectomy; Incidence; Peripartum Period; Placenta Accreta; Placenta Previa; Pregnancy; Prevalence; Ultrasonography, Prenatal
PubMed: 31722942
DOI: 10.1136/bmjopen-2019-031193 -
Obstetrics and Gynecology Feb 2021To identify and quantify risk factors for atonic postpartum hemorrhage. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To identify and quantify risk factors for atonic postpartum hemorrhage.
DATA SOURCES
PubMed, CINAHL, EMBASE, Web of Science, and and ClinicalTrials.gov databases were searched for English language studies with no restrictions on date or location. Studies included randomized trials, prospective or retrospective cohort studies, and case-control studies of pregnant patients who developed atonic postpartum hemorrhage and reported at least one risk factor.
METHODS OF STUDY SELECTION
Title, abstract, and full-text screening were performed using the Raayan web application. Of 1,239 records screened, 27 studies were included in this review. Adjusted or unadjusted odds ratios (ORs), relative risks, or rate ratios were recorded or calculated. For each risk factor, a qualitative synthesis of low and moderate risk of bias studies classifies the risk factor as definite, likely, unclear, or not a risk factor. For risk factors with sufficiently homogeneous definitions and reference ranges, a quantitative meta-analysis of low and moderate risk of bias studies was implemented to estimate a combined OR.
TABULATION, INTEGRATION, AND RESULTS
Forty-seven potential risk factors for atonic postpartum hemorrhage were identified in this review, of which 15 were judged definite or likely risk factors. The remaining 32 assessed risk factors showed no association with atonic postpartum hemorrhage or had conflicting or unclear evidence.
CONCLUSION
A substantial proportion of postpartum hemorrhage occurs in the absence of recognized risk factors. Many risk factors for atonic hemorrhage included in current risk-assessment tools were confirmed, with the greatest risk conferred by prior postpartum hemorrhage of any etiology, placenta previa, placental abruption, uterine rupture, and multiple gestation. Novel risk factors not currently included in risk-assessment tools included hypertension, diabetes, and ethnicity. Obesity and magnesium were not associated with atonic postpartum hemorrhage in this review.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO, CRD42020157521.
Topics: Female; Humans; Postpartum Hemorrhage; Pregnancy; Risk Factors; Uterine Inertia
PubMed: 33417319
DOI: 10.1097/AOG.0000000000004228 -
The Journal of Obstetrics and... May 2023To objectively assess the quality of the published clinical practice guidelines (CPGs) on the management of pregnancies complicated by placenta accreta spectrum... (Review)
Review
OBJECTIVES
To objectively assess the quality of the published clinical practice guidelines (CPGs) on the management of pregnancies complicated by placenta accreta spectrum (PAS)disorders.
METHODS
MEDLINE, Embase, Scopus, and ISI Web of Science databases were searched. The following aspects related to the management of pregnancies with suspected PAS disorders were evaluated: risk factors for PAS, prenatal diagnosis, role of interventional radiology and ureteral stenting, and optimal surgical management. The assessment of risk of bias and quality assessment of the CPGs were performed using the (AGREE II) tool (Brouwers et al., 2010). To define a CPG as of good quality we adopted a cut-off score >60%.
RESULTS
Nine CPGs were included. Specific risk factors for referral were assessed by 44.4% (4/9) of CPGs, mainly consisting in the presence of placenta previa and a prior cesarean delivery or uterine surgery. About 55.6% of CPGs (5/9) suggested ultrasound assessment of women with risk factors for PAS in the second and third trimester of pregnancy and 33.3% (3/9) recommended magnetic resonance imaging (MRI); 88.9% (8/9) of CPGs recommended cesarean delivery at 34-37 weeks of gestation. There was not generally consensus on the use of interventional radiology and ureteral stenting before surgery for PAS. Finally, hysterectomy was the recommend surgical approach by 77.8% (7/9) of the included CPGs.
CONCLUSION
Most of the published CPGs on PAS are generally of good quality. There was general agreement among the different CPGs on PAS as a regard as risk stratification, timing at diagnosis and delivery but not on the indication for MRI, use of interventional radiology and ureteral stenting.
Topics: Pregnancy; Female; Humans; Placenta Accreta; Prenatal Diagnosis; Placenta Previa; Cesarean Section; Pregnancy Trimester, Third; Retrospective Studies; Placenta; Ultrasonography, Prenatal
PubMed: 36796351
DOI: 10.1111/jog.15544 -
BJOG : An International Journal of... Jan 2021Postpartum haemorrhage (PPH) causes substantial morbidity and mortality worldwide. A reliable prognostic tool for PPH has potential to aid prevention efforts.
BACKGROUND
Postpartum haemorrhage (PPH) causes substantial morbidity and mortality worldwide. A reliable prognostic tool for PPH has potential to aid prevention efforts.
OBJECTIVE
Systematically to identify and appraise prognostic modelling studies for prediction of PPH.
SEARCH STRATEGY
MEDLINE, Embase, CINAHL and the Cochrane Library were searched using a combination of terms and synonyms including 'prediction tool', 'risk score' and 'postpartum haemorrhage'.
SELECTION CRITERIA
Any observational or experimental study developing a prognostic model for women's risk of PPH. English language publications.
DATA COLLECTION AND ANALYSIS
Predesigned data extraction form to record: data source; participant criteria; outcome; candidate predictors; actual predictors; sample size; missing data; model development; model performance; model evaluation; interpretation.
MAIN RESULTS
Of 2146 citations screened, 14 studies were eligible for inclusion. Studies addressed populations of women who experienced placenta praevia, placenta accreta spectrum, vaginal birth, caesarean birth (CS) and the general obstetric population. All studies were at high risk of bias due to low sample size, no internal validation, suboptimal or no external validation or no reporting or handling of missing data. Five studies raised applicability concerns. Three externally validated and three internally validated studies show potential for robust external validation.
CONCLUSION
Of 14 prognostic models for PPH risk, three have some potential for clinical use: in CS, in placenta accreta spectrum disorders with MRI placental Evaluation and in placenta praevia. Future research requires robust internal and external validation of existing tools and development of a model for use in the general obstetric population.
TWEETABLE ABSTRACT
Current PPH prediction tools need external validation: one for CS, one for placenta praevia and one for placenta accreta. Tools are needed for labouring women.
Topics: Female; Humans; Postpartum Hemorrhage; Predictive Value of Tests; Pregnancy; Prenatal Care; Prenatal Diagnosis; Risk Factors
PubMed: 32575159
DOI: 10.1111/1471-0528.16379 -
Journal of Minimally Invasive Gynecology Jun 2022To provide a systematic review of pregnancy outcomes after radiofrequency ablation (RFA) of uterine myomas. (Review)
Review
OBJECTIVE
To provide a systematic review of pregnancy outcomes after radiofrequency ablation (RFA) of uterine myomas.
DATA SOURCES
A literature search was conducted using PubMed, Cochrane Library, Scopus, Web of Science, and Embase, from database inception to October 2021.
METHODS OF STUDY SELECTION
Two reviewers conducted independent literature searches. Studies that met the criteria based on title and abstract underwent full-text review. Publications were included if they reported pregnancies and obstetric outcomes after laparoscopic or transcervical RFA of myomas.
TABULATION, INTEGRATION, AND RESULTS
A total of 405 publications were initially identified and screened, 39 underwent full-text review, and 10 publications were ultimately included. There were 50 pregnancies reported among 923 RFA patients: 40 pregnancies after 559 laparoscopic RFAs and 10 pregnancies after 364 transcervical RFAs. The number of patients from these studies actively trying to conceive after RFA is unknown. Among the RFA patients who conceived, the average age at ablation was 37 years old (range, 27-46 years). Most patients had between 1 and 3 myomas ablated, and myomas size ranged from <2 cm to 12.5 cm. There were 6 spontaneous abortions (12%) and 44 full-term pregnancies (88%), of which 24 were vaginal deliveries and 20 were cesarean deliveries. There were only 2 complications among 44 deliveries: one placenta previa that underwent an uncomplicated cesarean delivery and 1 delayed postpartum hemorrhage with expulsion of a degenerated myoma, with no long-term sequelae. There were no cases of uterine rupture, uterine window, or invasive placentation and no fetal complications. The spontaneous abortion rate was comparable with the general obstetric population.
CONCLUSION
Almost all pregnancies after RFA of myomas were full-term deliveries with no maternal or neonatal complications. These findings add to the literature that radiofrequency myoma ablation may offer a safe and effective alternative to existing treatments for women who desire future fertility.
Topics: Abortion, Spontaneous; Adult; Catheter Ablation; Female; Humans; Infant, Newborn; Leiomyoma; Myoma; Pregnancy; Pregnancy Outcome; Uterine Neoplasms
PubMed: 35123041
DOI: 10.1016/j.jmig.2022.01.015 -
Human Reproduction Update Sep 2023The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when natural cycle FET (NC-FET) is compared to artificial cycle FET (AC-FET) in subfertile women. However, NC-FET seems to be associated with lower risk of adverse obstetric and neonatal outcomes compared with AC-FET cycles. Currently, there is no consensus about whether NC-FET needs to be combined with luteal phase support (LPS) or not. The question of how to prepare the endometrium for FET has now gained even more importance and taken the dimension of safety into account as it should not simply be reduced to the basic question of effectiveness.
OBJECTIVE AND RATIONALE
The objective of this project was to determine whether NC-FET, with or without LPS, decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET.
SEARCH METHODS
A systematic review and meta-analysis was carried out. A literature search was performed using the following databases: CINAHL, EMBASE, and MEDLINE from inception to 10 October 2022. Observational studies, including cohort studies, and registries comparing obstetric and neonatal outcomes between singleton pregnancies after NC-FET and those after AC-FET were sought. Risk of bias was assessed using the ROBINS-I tool. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. We calculated pooled odds ratios (ORs), pooled risk differences (RDs), pooled adjusted ORs, and prevalence estimates with 95% CI using a random effect model, while heterogeneity was assessed by the I2.
OUTCOMES
The conducted search identified 2436 studies, 890 duplicates were removed and 1546 studies were screened. Thirty studies (NC-FET n = 56 445; AC-FET n = 57 231) were included, 19 of which used LPS in NC-FET. Birthweight was lower following NC-FET versus AC-FET (mean difference 26.35 g; 95% CI 11.61-41.08, I2 = 63%). Furthermore NC-FET compared to AC-FET resulted in a lower risk of large for gestational age (OR 0.88, 95% 0.83-0.94, I2 = 54%), macrosomia (OR 0.81; 95% CI 0.71-0.93, I2 = 68%), low birthweight (OR 0.81, 95% CI 0.77-0.85, I2 = 41%), early pregnancy loss (OR 0.73; 95% CI 0.61-0.86, I2 = 70%), preterm birth (OR 0.80; 95% CI 0.75-0.85, I2 = 20%), very preterm birth (OR 0.66, 95% CI 0.53-0.84, I2 = 0%), hypertensive disorders of pregnancy (OR 0.60, 95% CI 0.50-0.65, I2 = 61%), pre-eclampsia (OR 0.50; 95% CI 0.42-0.60, I2 = 44%), placenta previa (OR 0.84, 95% CI 0.73-0.97, I2 = 0%), and postpartum hemorrhage (OR 0.43; 95% CI 0.38-0.48, I2 = 53%). Stratified analyses on LPS use in NC-FET suggested that, compared to AC-FET, NC-FET with LPS decreased preterm birth risk, while NC-FET without LPS did not (OR 0.75, 95% CI 0.70-0.81). LPS use did not modify the other outcomes. Heterogeneity varied from low to high, while quality of the evidence was very low to moderate.
WIDER IMPLICATIONS
This study confirms that NC-FET decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET. We estimate that for each adverse outcome, use of NC-FET may prevent 4 to 22 cases per 1000 women. Consequently, NC-FET should be the preferred treatment in women with ovulatory cycles undergoing FET. Based on very low quality of evidence, the risk of preterm birth be decreased when LPS is used in NC-FET compared to AC-FET. However, because of many uncertainties-the major being the debate about efficacy of the use of LPS-future research is needed on efficacy and safety of LPS and no recommendation can be made about the use of LPS.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Birth Weight; Premature Birth; Luteal Phase; Lipopolysaccharides; Cryopreservation; Embryo Transfer; Pregnancy Rate; Retrospective Studies
PubMed: 37172270
DOI: 10.1093/humupd/dmad011 -
American Journal of Obstetrics and... Apr 2020To assess the efficacy, effectiveness, and safety of uterine balloon tamponade for treating postpartum hemorrhage. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To assess the efficacy, effectiveness, and safety of uterine balloon tamponade for treating postpartum hemorrhage.
STUDY DESIGN
We searched electronic databases (from their inception to August 2019) and bibliographies. We included randomized controlled trials, nonrandomized studies, and case series that reported on the efficacy, effectiveness, and/or safety of uterine balloon tamponade in women with postpartum hemorrhage. The primary outcome was the success rate of uterine balloon tamponade for treating postpartum hemorrhage (number of uterine balloon tamponade success cases/total number of women treated with uterine balloon tamponade). For meta-analyses, we calculated pooled success rate for all studies, and relative risk with 95% confidence intervals for studies that included a comparative arm.
RESULTS
Ninety-one studies, including 4729 women, met inclusion criteria (6 randomized trials, 1 cluster randomized trial, 15 nonrandomized studies, and 69 case series). The overall pooled uterine balloon tamponade success rate was 85.9% (95% confidence interval, 83.9-87.9%). The highest success rates corresponded to uterine atony (87.1%) and placenta previa (86.8%), and the lowest to placenta accreta spectrum (66.7%) and retained products of conception (76.8%). The uterine balloon tamponade success rate was lower in cesarean deliveries (81.7%) than in vaginal deliveries (87.0%). A meta-analysis of 2 randomized trials that compared uterine balloon tamponade vs no uterine balloon tamponade in postpartum hemorrhage due to uterine atony after vaginal delivery showed no significant differences between the study groups in the risk of surgical interventions or maternal death (relative risk, 0.59; 95% confidence interval, 0.02-16.69). A meta-analysis of 2 nonrandomized before-and-after studies showed that introduction of uterine balloon tamponade in protocols for managing severe postpartum hemorrhage significantly decreased the use of arterial embolization (relative risk, 0.29; 95% confidence interval, 0.14-0.63). A nonrandomized cluster study reported that use of invasive procedures was significantly lower in the perinatal network that routinely used uterine balloon tamponade than that which did not use uterine balloon tamponade (3.0/1000 vs 5.1/1000; P < .01). A cluster randomized trial reported that the frequency of postpartum hemorrhage-related invasive procedures and/or maternal death was significantly higher after uterine balloon tamponade introduction than before uterine balloon tamponade introduction (11.6/10,000 vs 6.7/10,000; P = .04). Overall, the frequency of complications attributed to uterine balloon tamponade use was low (≤6.5%).
CONCLUSION
Uterine balloon tamponade has a high success rate for treating severe postpartum hemorrhage and appears to be safe. The evidence on uterine balloon tamponade efficacy and effectiveness from randomized and nonrandomized studies is conflicting, with experimental studies suggesting no beneficial effect, in contrast with observational studies. Further research is needed to determine the most effective programmatic and healthcare delivery strategies on uterine balloon tamponade introduction and use.
Topics: Cesarean Section; Female; Humans; Maternal Mortality; Parturition; Placenta Accreta; Placenta Previa; Placenta, Retained; Postpartum Hemorrhage; Pregnancy; Uterine Artery Embolization; Uterine Balloon Tamponade; Uterine Inertia
PubMed: 31917139
DOI: 10.1016/j.ajog.2019.11.1287 -
American Journal of Obstetrics &... Aug 2023This systematic review and meta-analysis aimed to assess clinical characteristics related to pathologically proven placenta accreta spectrum without placenta previa. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review and meta-analysis aimed to assess clinical characteristics related to pathologically proven placenta accreta spectrum without placenta previa.
DATA SOURCES
A literature search of PubMed, the Cochrane database, and Web of Science was performed from inception to September 7, 2022.
STUDY ELIGIBILITY CRITERIA
The primary outcomes were invasive placenta (including increta or percreta), blood loss, hysterectomy, and antenatal diagnosis. In addition, maternal age, assisted reproductive technology, previous cesarean delivery, and previous uterine procedures were investigated as potential risk factors. The inclusion criteria were studies evaluating the clinical presentation of pathologically diagnosed PAS without placenta previa.
METHODS
Study screening was conducted after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis.
RESULTS
Among 2598 studies that were initially retrieved, 5 were included in the review. With the exception of 1 study, 4 studies were included in the meta-analysis. This meta-analysis showed that placenta accreta spectrum without placenta previa was associated with less risk of invasive placenta (odds ratio, 0.24; 95% confidence interval, 0.16-0.37), blood loss (mean difference, -1.19; 95% confidence interval, -2.09 to -0.28) and hysterectomy (odds ratio, 0.11; 95% confidence interval, 0.02-0.53), and more difficult to diagnose prenatally (odds ratio, 0.13; 95% confidence interval, 0.04-0.45) than placenta accreta spectrum with placenta previa. In addition, assisted reproductive technology and a previous uterine procedure were strong risk factors for placenta accreta spectrum without placenta previa, whhereas previous cesarean delivery was a strong risk factor for placenta accreta spectrum with placenta previa.
CONCLUSION
The differences in clinical aspects of placenta accreta spectrum with and without placenta previa need to be understood.
Topics: Pregnancy; Female; Humans; Placenta Accreta; Retrospective Studies; Placenta Previa; Hysterectomy; Risk Factors
PubMed: 37211089
DOI: 10.1016/j.ajogmf.2023.101027 -
American Journal of Obstetrics &... Aug 2020To systematically review published literature and calculate the prevalence of vasa previa and its known risk factors. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To systematically review published literature and calculate the prevalence of vasa previa and its known risk factors.
MATERIALS AND METHODS
MEDLINE, Embase, the Cochrane Library, PubMed (non-MEDLINE and in process), and www.clinicaltrials.gov were searched from inception to March 2018 using indexing terms "vasa previa," "placenta previa," "low lying placenta," "succenturiate lobe," "bilobate placenta," "bilobed placenta," and "velamentous insertion." All original research studies reporting on 5 or more pregnancies with vasa previa were included. The search was limited to studies on human data and those published in the English language. Two reviewers independently screened titles and abstracts, completed data extraction, and assessed reporting quality using the Study Quality Assessment Tool for Case Series Studies of the National Heart, Lung, and Blood Institute. Disagreements were discussed and resolved at each step of the process.
RESULTS
We included 21 studies that reported 428 pregnancies with vasa previa of 1,027,918 deliveries (0.46 cases of vasa previa per 1000 deliveries). These studies fared well on risk of bias assessment using the Study Quality Assessment Tool for Case Series Studies of the National Heart, Lung, and Blood Institute. The prevalence and 95% confidence intervals of known risk factors for vasa previa included a low-lying placenta (61.5%, 53.0%-70.0%), velamentous cord insertion (52.2%, 39.6%-64.7%), bilobed or succenturiate lobed placenta (33.3%, 20.9%-45.7%), use of in vitro fertilization (26.4%, 16.0%-36.8%), and multiple gestation (8.92%, 5.33%-12.5%).
CONCLUSION
Vasa previa affects 0.46 cases per 1000 pregnancies. Given the high prevalence of prenatally detectable risk factors in affected pregnancies, the cost-effectiveness of screening strategies for vasa previa either in isolation, using a risk factor-based approach, or universally, in tandem with cervical-length screening using transvaginal ultrasound, should be revisited.
Topics: Female; Humans; Placenta; Placenta Previa; Pregnancy; Risk Factors; Ultrasonography, Prenatal; Vasa Previa
PubMed: 33345868
DOI: 10.1016/j.ajogmf.2020.100117 -
Biomedicines Feb 2022This study aimed to assess the relationship between placenta accreta spectrum disorder (PASD) and endometriosis. The relationships among pregnancy, assisted reproductive... (Review)
Review
This study aimed to assess the relationship between placenta accreta spectrum disorder (PASD) and endometriosis. The relationships among pregnancy, assisted reproductive technology (ART), placenta previa, ART-conceived pregnancy and PASD were also determined. A systematic literature review was conducted using multiple computerized databases. Forty-eight studies (1990-2021) met the inclusion criteria. According to the adjusted pooled analysis ( = 3), endometriosis was associated with an increased prevalence of PASD (adjusted odds ratio [OR] 3.39, 95% confidence interval [CI] 1.96-5.87). In the included studies, the ART rate ranged from 18.2% to 37.2% for women with endometriosis. According to the adjusted pooled analysis, women who used ART were more likely to have placenta previa ( = 13: adjusted OR 2.96, 95%CI, 2.43-3.60) and PASD ( = 4: adjusted OR 3.54, 95%CI 1.86-6.76) than those who did not use ART. According to the sensitivity analysis using an unadjusted analysis accounting for the type of ART, frozen embryo transfer (ET) was associated with an increased risk of PASD ( = 4: OR 2.79, 95%CI, 1.22-6.37) compared to fresh ET. Endometriosis may be associated with an increased rate of PASD. Women with placenta previa complicated with endometriosis who conceived using frozen ET may be a high risk for PASD.
PubMed: 35203599
DOI: 10.3390/biomedicines10020390