-
American Journal of Obstetrics and... Jul 2017Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta.
OBJECTIVE
The objective of the study was to evaluate the accuracy of ultrasound imaging in the prenatal diagnosis of placenta accreta and the impact of the depth of villous invasion on management in women presenting with placenta previa or low-lying placenta and with 1 or more prior cesarean deliveries.
STUDY DESIGN AND DATA SOURCES
We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE for studies published between 1982 and November 2016.
STUDY ELIGIBILITY CRITERIA
Criteria for the study were cohort studies that provided data on previous mode of delivery, placenta previa, or low-lying placenta on prenatal ultrasound imaging and pregnancy outcome. The initial search identified 171 records, of which 5 retrospective and 9 prospective cohort studies were eligible for inclusion in the quantitative analysis.
STUDY APPRAISAL AND SYNTHESIS METHODS
The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool.
RESULTS
The 14 cohort studies included 3889 pregnancies presenting with placenta previa or low-lying placenta and 1 or more prior cesarean deliveries screened for placenta accreta. There were 328 cases of placenta previa accreta (8.4%), of which 298 (90.9%) were diagnosed prenatally by ultrasound. The incidence of placenta previa accreta was 4.1% in women with 1 prior cesarean and 13.3% in women with ≥2 previous cesarean deliveries. The pooled performance of ultrasound for the antenatal detection of placenta previa accreta was higher in prospective than retrospective studies, with a diagnostic odds ratios of 228.5 (95% confidence interval, 67.2-776.9) and 80.8 (95% confidence interval, 13.0-501.4), respectively. Only 2 studies provided detailed data on the relationship between the depth of villous invasion and the number of previous cesarean deliveries, independently of the depth of the villous invasion. A cesarean hysterectomy was performed in 208 of 232 cases (89.7%) for which detailed data on management were available. Positive correlations were found in the largest prospective studies between the cumulative rates of the more invasive forms of accreta placentation and the sensitivity and specificity of ultrasound imaging but not with diagnostic odds ratio values. We found no data on the ultrasound screening of placenta accreta at the routine midtrimester ultrasound examination from the nonexpert ultrasound units.
CONCLUSION
Planning individual management for delivery is possible only with accurate evaluation of prenatal risk of accreta placentation in women presenting with a low-lying placenta/previa and a history of prior cesarean delivery. Ultrasound is highly sensitive and specific in the prenatal diagnosis of accreta placentation when performed by skilled operators. Developing a prenatal screening protocol is now essential to further improve the outcome of this increasingly more common major obstetric complication.
Topics: Cesarean Section; Female; Humans; Hysterectomy; MEDLINE; Placenta Accreta; Placenta Previa; Placentation; Pregnancy; Pregnancy Outcome; Prospective Studies; Retrospective Studies; Risk Factors; Sensitivity and Specificity; Ultrasonography, Prenatal
PubMed: 28268196
DOI: 10.1016/j.ajog.2017.02.050 -
European Journal of Obstetrics,... Apr 2021Placenta accreta spectrum (PAS) is an umbrella term for a variety of pregnancy complications due to abnormal placental implantation, including placenta accreta, placenta... (Review)
Review
Placenta accreta spectrum (PAS) is an umbrella term for a variety of pregnancy complications due to abnormal placental implantation, including placenta accreta, placenta increta and placenta percreta. During the past several decades, the prevalence of PAS has been increasing, and the clinical importance of this disease is significant because of the severe complications. In this review, we summarized the available evidence-based data for PAS in various aspects: prevalence, risk factors, pathogenesis, clinical presentation and prenatal screening, and clinical management. Meanwhile, we provided a series of prospects in each section for further studies on PAS. Moreover, we first present a visualized workflow for the management of PAS from three steps: predelivery, during delivery and postdelivery.
Topics: Female; Humans; Placenta; Placenta Accreta; Placenta Previa; Pregnancy; Prenatal Diagnosis; Risk Factors
PubMed: 33601317
DOI: 10.1016/j.ejogrb.2021.02.001 -
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 -
CMAJ : Canadian Medical Association... Aug 2020
Review
Topics: Cesarean Section; Female; Humans; Hysterectomy; Placenta Accreta; Placenta Previa; Pregnancy; Risk Factors
PubMed: 32839166
DOI: 10.1503/cmaj.200304 -
Anesthesia and Pain Medicine Oct 2020Patients with placenta previa are at risk for intra- and postpartum massive blood loss as well as increased risk of placenta accreta, a type of abnormal placental... (Review)
Review
Patients with placenta previa are at risk for intra- and postpartum massive blood loss as well as increased risk of placenta accreta, a type of abnormal placental implantation. This condition can lead to serious obstetric complications, including maternal mortality and morbidity. The risk factors for previa include prior cesarean section, multiparity, advanced maternal age, prior placenta previa history, prior uterine surgery, and smoking. The prevalence of previa parturients has increased due to the rising rates of cesarean section and advanced maternal age. For these reasons, we need to identify the risk factors for previa and identify adequate management strategies to respond to blood loss during surgery. This review evaluated the diagnosis of placenta previa and placenta accreta and assessed the risk factors for previa-associated bleeding prior to cesarean section. We then presented intraoperative anesthetic management and other interventions to control bleeding in patients with previa expected to experience massive hemorrhage and require transfusion.
PubMed: 33329843
DOI: 10.17085/apm.20076 -
American Journal of Obstetrics and... Sep 2020The evolution of multidisciplinary team-based care for women with placenta accreta spectrum disorder has delivered stepwise improvements in clinical outcomes. Central to... (Review)
Review
The evolution of multidisciplinary team-based care for women with placenta accreta spectrum disorder has delivered stepwise improvements in clinical outcomes. Central to this overall goal is the ability to limit blood loss at surgery. Placement of inflatable balloons within the pelvic arteries, most commonly in the anterior divisions of the internal iliac arteries, became popular in many centers, at the expense of prolonging surgical care and with attendant risks of vascular injury. In tandem, the need to expose pelvic sidewall anatomy to safely identify the course of the ureters re-popularized the alternative strategy of ligating the same anterior divisions of the internal iliac arteries. With incremental gains in surgical expertise, described in 5 steps in this review, our teams have witnessed a steady decline in surgical blood loss. Nevertheless, a subset of women has the most severe form of placenta accreta spectrum, namely placenta previa-percreta. Such women are at risk of major hemorrhage during surgery from vessels arising outside the territories of the internal iliac arteries. These additional blood supplies, mostly from the external iliac arteries, pose significant risks of major blood loss even in experienced hands. To address this risk, some centers, principally in China, have adopted an approach of routinely placing an infrarenal aortic balloon, with both impressively low rates of blood loss and an ability to conserve the uterus by resecting the placenta with the affected portion of the uterine wall. We review these literature developments in the context of safely performing elective cesarean hysterectomy for placenta previa-percreta, the most severe placenta accreta spectrum disorder.
Topics: Balloon Occlusion; Blood Loss, Surgical; Cesarean Section; Colpotomy; Female; Humans; Hysterectomy; Iliac Artery; Ligation; Magnetic Resonance Imaging; Placenta Accreta; Placenta Previa; Pregnancy; Risk Factors; Treatment Outcome
PubMed: 32007492
DOI: 10.1016/j.ajog.2020.01.044 -
Best Practice & Research. Clinical... Nov 2019The increasing incidence of caesarean delivery (CD) has resulted in an increase in placenta accreta spectrum (PAS), adversely impacting maternal outcomes globally.... (Review)
Review
The increasing incidence of caesarean delivery (CD) has resulted in an increase in placenta accreta spectrum (PAS), adversely impacting maternal outcomes globally. Currently, more than 90% of women diagnosed with PAS present with a placenta praevia (praevia PAS). Praevia PAS can be reliably diagnosed antenatally with ultrasound, and it is unclear whether magnetic resonance imaging improves diagnosis beyond what can be achieved by skilled ultrasound operators. Therefore, any screening programme for PAS will require improved training in the diagnosis of placental disorders and development of targeted scanning protocols. Management strategies for praevia PAS vary depending on the accuracy of prenatal diagnosis, findings at laparotomy and local surgical expertise. Current epidemiological data for PAS are highly heterogeneous, mainly due to wide variation in the clinical criteria used to diagnose the condition at birth. This significantly impacts research into all aspects of the condition, especially comparison of the efficacy of different management strategies.
Topics: Cesarean Section; Female; Humans; Magnetic Resonance Imaging; Placenta Accreta; Placenta Previa; Pregnancy; Prenatal Diagnosis
PubMed: 31126811
DOI: 10.1016/j.bpobgyn.2019.04.006 -
Fertility and Sterility Feb 2020The use of frozen-thawed embryo transfer (FET) has increased over the past decade with improvements in technology and increasing live birth rates. FET facilitates... (Review)
Review
The use of frozen-thawed embryo transfer (FET) has increased over the past decade with improvements in technology and increasing live birth rates. FET facilitates elective single-embryo transfer, reduces ovarian hyperstimulation syndrome, optimizes endometrial receptivity, allows time for preimplantation genetics testing, and facilitates fertility preservation. FET cycles have been associated, however, with an increased risk of hypertensive disorders of pregnancy for reasons that are not clear. Recent evidence suggests that absence of the corpus luteum (CL) could be at least partly responsible for this increased risk. In a recent prospective cohort study, programmed FET cycles (no CL) were associated with higher rates of preeclampsia and preeclampsia with severe features compared with modified natural FET cycles. FET cycles are commonly performed in the context of a programmed cycle in which the endometrium is prepared with the use of exogenous E and P. In these cycles, ovulation is suppressed and therefore the CL is absent. The CL produces not only E and P, but also vasoactive products, such as relaxin and vascular endothelial growth factor, which are not replaced in a programmed FET cycle and which are hypothesized to be important for initial placentation. Emerging evidence has also revealed other adverse obstetrical and perinatal outcomes, including postpartum hemorrhage, macrosomia, and post-term birth specifically in programmed FET cycles compared with natural FET cycles. Despite the widespread use of FET, the optimal protocol with respect to live birth rate, maternal health, and perinatal outcomes has yet to be determined. Future practice regarding FET should be based on high-quality evidence, including rigorous controlled trials.
Topics: Adaptation, Physiological; Corpus Luteum; Cryopreservation; Embryo Transfer; Female; Humans; Infant, Low Birth Weight; Placenta Previa; Pre-Eclampsia; Pregnancy; Pregnancy Outcome
PubMed: 32106972
DOI: 10.1016/j.fertnstert.2019.12.007 -
Taiwanese Journal of Obstetrics &... Dec 2018The aim is to examine risk factors and neonatal outcomes of preterm birth and to provide basis in preventing preterm birth.
OBJECTIVE
The aim is to examine risk factors and neonatal outcomes of preterm birth and to provide basis in preventing preterm birth.
MATERIALS AND METHODS
we carried out our study on 1328 term controls and 1328 preterm birth cases. By using multivariable logistic regression procedures we estimated odds ratio (OR) of potential preterm birth risk factors. T-test and chi-square test were used to estimate differences between groups.
RESULTS
Maternal age, prior history of pregnancy and abortion, prenatal care, complications of pregnancy (includes hypertension, intrahepatic cholestasis of pregnancy (ICP), fetal growth restriction (FGR), premature rupture of the membranes (PROM), placenta previa, abnormal presentation, abnormal S/D ratio et al.) were significantly associated with preterm birth. Several factors emerged as being statistically significant risk factors for preterm birth, such as prior history of pregnancy, hypertension, ICP, FGR, PROM, placenta previa and abnormal presentation. The time of prenatal care was shown to be a protective factor. Additionally, we observed evidence suggested that male babies are known to have a significant higher risk of preterm birth than female babies.
CONCLUSION
Prior history of pregnancy, hypertension, ICP, FGR, PROM, placenta previa and abnormal presentation were covariates identified in this study as risk factors for preterm birth. Preterm birth is an important reason of neonatal poor prognosis and death.
Topics: Adult; Age Factors; Case-Control Studies; China; Female; Fetal Growth Retardation; Fetal Membranes, Premature Rupture; Gestational Age; Humans; Infant, Newborn; Logistic Models; Male; Placenta Previa; Pregnancy; Pregnancy Outcome; Premature Birth; Prenatal Care; Risk Factors; Young Adult
PubMed: 30545533
DOI: 10.1016/j.tjog.2018.10.008