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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 -
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 -
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 &... 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 -
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 -
Journal of Clinical Medicine Feb 2021This systematic review and meta-analysis summarizes the evidence for the association between endometriosis and adverse pregnancy outcome, including gestational... (Review)
Review
BACKGROUND
This systematic review and meta-analysis summarizes the evidence for the association between endometriosis and adverse pregnancy outcome, including gestational hypertension, pre-eclampsia, low birth weight, and small for gestational age, preterm birth, placenta previa, placental abruption, cesarean section, stillbirth, postpartum hemorrhage, spontaneous hemoperitoneum in pregnancy, and spontaneous bowel perforation in pregnancy.
METHODS
We performed the literature review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), by searches in PubMed and EMBASE, until 1 November 2020 (PROSPERO ID CRD42020213999). We included peer-reviewed observational cohort studies and case-control studies and scored them according to the Newcastle-Ottawa Scale, to assess the risk of bias and confounding.
RESULTS
39 studies were included. Women with endometriosis had an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth, compared to women without endometriosis. These results remained unchanged in sub-analyses, including studies on spontaneous pregnancies only. Spontaneous hemoperitoneum in pregnancy and bowel perforation seemed to be associated with endometriosis; however, the studies were few and did not meet the inclusion criteria.
CONCLUSIONS
The literature shows that endometriosis is associated with an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth.
PubMed: 33572322
DOI: 10.3390/jcm10040667 -
Journal of Global Health Jun 2024As birth policy can affect maternal and infant health, we sought to identify whether and how the introduction of the two-child policy might have affected the prevalence... (Meta-Analysis)
Meta-Analysis
BACKGROUND
As birth policy can affect maternal and infant health, we sought to identify whether and how the introduction of the two-child policy might have affected the prevalence of placenta previa in pregnant women in mainland China.
METHODS
In this update meta-analysis and systematic review, we searched PubMed, Web of Science, the Cochrane Library, Weipu, Wanfang, and the China National Knowledge Infrastructure (CNKI) databases for studies evaluating the prevalence of placenta previa in China published between the inception of each database and March 2024, with no restrictions. Two investigators independently extracted the data from each included study. We then combined the prevalence of placenta previa using random-effects models.
RESULTS
We included 128 studies in our analysis, 48 more than in our previous review. The prevalence of placenta previa among Chinese pregnant women was 1.44% (95% confidence interval (CI) = 1.32, 1.56). After the implementation of the two-child policy, the prevalence increased significantly, from 1.25% (95% CI = 1.16, 1.34) to 4.12% (95% CI = 3.33, 4.91).
CONCLUSIONS
The prevalence of placenta previa increased significantly from the one-child policy period to the two-child policy period among mainland Chinese pregnant women, with varying trends across regions. This change requires the attention of health officials and timely adjustment of resource allocation policies.
REGISTRATION
PROSPERO: CRD42021262309.
Topics: Humans; Pregnancy; China; Female; Placenta Previa; Prevalence; Delivery, Obstetric
PubMed: 38867677
DOI: 10.7189/jogh.14.04108 -
Journal of Obstetrics and Gynaecology :... Dec 2024Vaginal bleeding during pregnancy has been recognised as a significant risk factor for adverse pregnancy outcomes. This study aimed to investigate the association... (Meta-Analysis)
Meta-Analysis Review
Vaginal bleeding during pregnancy has been recognised as a significant risk factor for adverse pregnancy outcomes. This study aimed to investigate the association between vaginal bleeding during the first trimester of pregnancy and clinical adverse effects using a systematic review and meta-analysis. Databases of Scopus, Web of Science, PubMed (including Medline), Cochrane Library and Science Direct were searched until June of 2023. Data analysis using statistical test fixed- and random-effects models in the meta-analysis, Cochran and meta-regression. The quality of the eligible studies was assessed by using the Newcastle-Ottawa Scale checklist (NOS). A total of 46 relevant studies, with a sample size of 1,554,141 were entered into the meta-analysis. Vaginal bleeding during the first trimester of pregnancy increases the risk of preterm birth (OR: 1.8, CI 95%: 1.6-2.0), low birth weight (LBW; OR: 2.0, CI 95%: 1.5-2.6), premature rupture of membranes (PROMs; OR: 2.3, CI 95%: 1.8-3.0), abortion (OR: 4.3, CI 95%: 2.0-9.0), stillbirth (OR: 2.5, CI 95%: 1.2-5.0), placental abruption (OR: 2.2, CI 95%: 1.4-3.3) and placenta previa (OR: 1.9, CI 95%: 1.5-2.4). Vaginal bleeding in the first trimester of pregnancy is associated with preterm birth, LBW, PROMs, miscarriage, stillbirth, placental abruption and placenta previa. Therefore, physicians or midwives need to be aware of the possibility of these consequences and manage them when they occur.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Stillbirth; Premature Birth; Abruptio Placentae; Placenta Previa; Placenta; Pregnancy Outcome; Abortion, Spontaneous; Uterine Hemorrhage
PubMed: 38305047
DOI: 10.1080/01443615.2023.2288224 -
Biomedicines Dec 2022Vasa previa is a rare fetal life-threatening obstetric disease classified into types I and II. This study aimed to examine the characteristics and obstetric outcomes of... (Review)
Review
Vasa previa is a rare fetal life-threatening obstetric disease classified into types I and II. This study aimed to examine the characteristics and obstetric outcomes of type II vasa previa. A systematic review was performed, and 20 studies (1998-2022) were identified. The results from six studies showed that type II vasa previa accounted for 21.3% of vasa previa cases. The characteristics and obstetric outcomes (rate of assisted reproductive technology (ART), antenatal diagnosis, emergent cesarean delivery, maternal transfusion, gestational age at delivery, and neonatal mortality) were compared between type I and II vasa previa, and all outcomes of interest were similar. The association between ART and abnormal placenta (bilobed placenta or succenturiate lobe) was examined in three studies, and the results were as follows: () increased rate of succenturiate lobes (ART versus non-ART pregnancy; OR (odds ratio) 6.97, 95% confidence interval (CI) 2.45-19.78); () similar rate of abnormal placenta (cleavage-stage versus blastocyst embryo transfer); () increased rate of abnormal placenta (frozen versus fresh embryo transfer; OR 2.97, 95%CI 1.10-7.96). Although the outcomes of type II vasa previa appear to be similar to those of type I vasa previa, the current evidence is insufficient for a robust conclusion.
PubMed: 36552018
DOI: 10.3390/biomedicines10123263 -
Reproductive Biology and Endocrinology... Jun 2023This systematic review and meta-analysis aimed to explore the relationship of endometrial thickness (EMT) with obstetric and neonatal outcomes in assisted reproductive... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
This systematic review and meta-analysis aimed to explore the relationship of endometrial thickness (EMT) with obstetric and neonatal outcomes in assisted reproductive cycles.
METHODS
PubMed, EMBASE, Cochrane Library and Web of Science were searched for eligible studies through April 2023. Obstetric outcomes include placenta previa, placental abruption, hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM) and cesarean section (CS). Neonatal outcomes include birthweight, low birth weight (LBW), gestational age (GA), preterm birth (PTB), small for gestational age (SGA) and large for gestational age (LGA). The effect size was estimated as odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) using a random-effects model. Inter-study heterogeneity was assessed by the chi-square homogeneity test. One-study removal method was used to determine the sensitivity of the meta-analysis.
RESULTS
Nineteen studies involving 76,404 cycles were included. The pooled results revealed significant differences between the thin endometrium group and the normal group in placental abruption (OR = 2.45, 95% CI: 1.11-5.38, P = 0.03; I = 0%), HDP (OR = 1.72, 95% CI: 1.44-2.05, P < 0.0001; I = 0%), CS (OR = 1.33, 95% CI: 1.06-1.67, P = 0.01; I = 77%), GA (MD = -1.27 day, 95% CI: -2.41- -1.02, P = 0.03; I = 73%), PTB (OR = 1.56, 95% CI: 1.34-1.81, P < 0.0001; I = 33%), birthweight (MD = -78.88 g, 95% CI: -115.79- -41.98, P < 0.0001; I = 48%), LBW (OR = 1.84, 95% CI: 1.52-2.22, P < 0.00001; I = 3%) and SGA (OR = 1.41, 95% CI: 1.17-1.70, P = 0.0003; I = 15%). No statistical differences were found in placenta previa, GDM, and LGA.
CONCLUSION
Thin endometrium was associated with lower birthweight or GA and higher risks of placental abruption, HDP, CS, PTB, LBW and SGA. Therefore, these pregnancies need special attention and close follow-up by obstetricians. Due to the limited number of included studies, further studies are needed to confirm the results.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Birth Weight; Abruptio Placentae; Cesarean Section; Placenta; Placenta Previa; Premature Birth; Diabetes, Gestational
PubMed: 37312205
DOI: 10.1186/s12958-023-01105-6