471 research outputs found
Prevalence and main outcomes of placenta accreta spectrum: a systematic review and metaanalysis
OBJECTIVE: The objective of this study was to evaluate the prevalence of placenta accreta spectrum in general population studies and the main maternal outcomes at delivery. STUDY DESIGN: Data sources: We searched PubMed, Google Scholar, clinicalTrials.gov and MEDLINE between 1982 and 2018. STUDY ELIGIBILITY CRITERIA: Articles providing data on the number of cases of placenta accreta spectrum per pregnancies, births or deliveries in a defined population. STUDY APPRAISAL AND SYNTHESIS METHODS: Study characteristics were evaluated by two independent reviewers using a predesigned protocol. Primary outcomes were the prevalence of placenta accreta spectrum and clinical diagnostic at birth and pathologic criteria used to confirm the diagnosis. Secondary outcomes included cases requiring transfusion, incidence of peripartum hysterectomy and maternal mortality rates. Heterogeneity between studies was analysed with the Cochran's Q-test and the I2 statistics. RESULTS: Of the 98 full-text studies identified, 29 articles met the defined criteria including 22 retrospective and 7 prospective studies comprising 7,001 cases of placenta accreta spectrum out 5,719,992 births. Prevalence rates ranged between 0.01 and 0.1% with an overall pooled prevalence of 0.17% (95% CI 0.14-0.19). Only 10 studies provided with detailed histopathologic data. The pool prevalence for the adherent versus the invasive grades was 0.5 (95% CI 0.3-0.36) and 0.3 (95% CI 0.2-0.4) per 1000 births, respectively. The pooled incidence for peripartum hysterectomy was 52.2% (95% CI 38.3-66.4; I2= 99.8%) and 46.9% (95 % CI 34-59.9, I2= 98.8%) for haemorrhage requiring transfusion. The pooled estimate of maternal death was 0.05% (95% CI 0.06-0.69, I2=73%). We found large amounts of heterogeneity between studies for all parameters and further quantifying was limited because of methodological inconsistencies between studies with regards to clinical criteria used for the diagnosis of the condition at birth and the histopathologic confirmation of the diagnosis and differential diagnosis between adherent and invasive accreta placentation. CONCLUSIONS: This meta-analysis indicates wide variation between studies for the prevalence rate of placenta accreta spectrum and for the different grades of accreta placentation, highlighting the need for consistency in definitions used to describe placenta accreta spectrum at birth and in reporting on this increasing common obstetric complication
Successful delivery after vaginal occlusion in addition to cerclage in a trachelectomy patient with recurrent second trimester pregnancy loss:a case report
KEY CLINICAL MESSAGE: Pregnancy outcome after trachelectomy has high risk of complications such as second trimester pregnancy loss and preterm birth. We report beneficial effect of a simple procedure of vaginal occlusion in addition to cerclage in a patient with trachelectomy and two prior second trimester pregnancy losses
Placenta accreta:adherent placenta due to Asherman syndrome
It is important to be aware of the risk of abnormally invasive placenta in patients with a history of Asherman syndrome and uterine scarring. A prenatal diagnosis by ultrasonography is useful when planning of mode of delivery
Epidemiology of placenta previa accreta: a systematic review and 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 0.39â1.24) whereas the
median prevalence of placenta previa with PAS was 0.07%
(IQR 0.05â0.16). The incidence of PAS in women with a
placenta previa was 11.10% (IQR 7.65â17.35).
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 CRD4201706858
Reference population for international comparisons and time trend surveillance of preterm delivery proportions in three countries
<p>Abstract</p> <p>Background</p> <p>International comparison and time trend surveillance of preterm delivery rates is complex. New techniques that could facilitate interpretation of such rates are needed.</p> <p>Methods</p> <p>We studied all live births and stillbirths (⼠28 weeks gestation) registered in the medical birth registers in Sweden, Denmark and Norway from 1995 through 2004. Gestational age was determined by best estimate. A reference population of pregnant women was designed using the following criteria: 1) maternal age 20â35, 2) primiparity, 3) spontaneously conceived pregnancy, 4) singleton pregnancy and 5) mother born in the respective country. National preterm delivery rate, preterm delivery rate in the reference population and rate of spontaneous preterm delivery in the reference population were calculated for each country.</p> <p>Results</p> <p>The total national preterm delivery rate (< 37 completed gestational weeks), increased in both Denmark (5.3% to 6.1%, p < 0.001) and Norway (6.0% to 6.4%, p = 0.006), but remained unchanged in Sweden, during 1995â2004. In Denmark, the preterm delivery rate in the reference population (5.3% to 6.3%, p < 0.001) and the spontaneous preterm delivery rate in the reference population (4.4% to 6.8%, p < 0.001) increased significantly. No similar increase was evident in Norway. In Sweden, rates in the reference population remained stable.</p> <p>Conclusion</p> <p>Reference populations can facilitate overview and thereby explanations for changing preterm delivery rates. The model also permits comparisons over time. This model may in its simplicity prove to be a valuable supplement to assessments of national preterm delivery rates for public health surveillance.</p
The increasing trend in preterm birth in public hospitals in northern Argentina
Objective: To identify factors associated with the increasing incidence of preterm birth in northern Argentina. Methods: In an observational study, data were reviewed from a prospective, population-based registry of pregnancy outcomes in six cities in 2009-2012. The primary outcome was preterm birth (at 20-37 weeks). Bivariate tests and generalized estimating equations were used within a conceptual hierarchical framework to estimate the cluster-corrected annual trend in odds of preterm birth. Results: The study reviewed data from 11 433 live births. There were 484 (4.2%) preterm births. The incidence of preterm births increased by 38% between 2009 and 2012, from 37.5 to 51.7 per 1000 live births. Unadjusted risk factors for preterm birth included young or advanced maternal age, normal body mass index, nulliparity, no prenatal care, no vitamins or supplements during pregnancy, multiple gestation, and maternal hypertension or prepartum hemorrhage. The prevalence of many risk factors increased over the study period, but variations in these factors explained less than 1% of the increasing trend in preterm birth. Conclusion: The incidence of preterm births insix small cities in northern Argentina increased greatly between 2009 and 2012. This trend was unexplained by the risk factors measured. Other factors should be assessed in future studies.Fil: Weaver, Emily H.. University of North Carolina School at Chapel Hill; Estados UnidosFil: Gibbons, Luz. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Belizan, Jose. Instituto de Efectividad ClĂnica y Sanitaria; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas; ArgentinaFil: Althabe, Fernando. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas; Argentina. Instituto de Efectividad ClĂnica y Sanitaria; Argentin
Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces
Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F+H2 yields HF+H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces
Etiology of individual differences in birth weight of twins as a function of maternal smoking during pregnancy
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