Background:Uncontrolled increase of C-section is one of the major problems in Iranian health system, such that C-section is the most common surgical procedure in the entire country’s hospitals in Obstetrics and Gynecology sections. A variety of complications also come along with cesarean. Objective:The aim of this study was to evaluate the prevalence, causes, and complications of cesarean in Iran.Materials and Methods:forty-one articles were considered with respect to certain criteria and were included in a systematic review to perform a meta-analysis study. The systematic review’s search was conducted on SID, Iranmedx, Magiran, Medlib, PubMed, and Science Direct databases published between1999-2016. The weight of each included study was calculated according to its sample size and the reported prevalence of binomial distribution. A random-effects model using R and STATA (Version 11.2) software was utilized for analyzing data Results:The total number of the sample was 197514 pregnant women with a mean age of 26.72 yr. The prevalence of cesarean in Iran was estimated at 48%. The main reasons for the prevalence of cesarean in this study were mothers’ higher education, previous cesarean, and doctor recommendation. The most frequent complication in women undergoing cesarean was the muscular pain, and the most common fetal complications in newborns by caesarean delivery was transient tachypnea.Conclusion:The prevalence of C-section in Iran is much higher than what WHO recommends. It is essential, to decrease such a phenomenon, making the mothers aware of the risks of cesarean delivery, and establishing counselling sessions as well to eliminate the mothers’ fear of vaginal delivery.

Background and objectives With the increase in the number of COVID-19 infections, the global health apparatus is facing insufficient resources. The main objective of the current study is to provide additional data regarding the clinical characteristics of the patients diagnosed with COVID-19, and in particular to analyze the factors associated with disease severity, lack of improvement, and mortality. Methods 102 studies were included in the present meta-analysis, all of which were published before September 24, 2020. The studies were found by searching a number of databases, including Scopus, MEDLINE, Web of Science, and Embase. We performed a thorough search from early February until September 24. The selected papers were evaluated and analyzed using Stata software application version 14. Results Ultimately, 102 papers were selected for this meta- analysis, covering 121,437 infected patients. The mean age of the patients was 58.42 years. The results indicate a prevalence of 79.26% for fever (95% CI: 74.98–83.26; I2 = 97.35%), 60.70% for cough (95% CI: 56.91–64.43; I2 = 94.98%), 33.21% for fatigue or myalgia (95% CI: 28.86–37.70; I2 = 96.12%), 31.30% for dyspnea (95% CI: 26.14–36.69; I2 = 97.67%), and 10.65% for diarrhea (95% CI: 8.26–13.27; I2 = 94.20%). The prevalence for the most common comorbidities was 28.30% for hypertension (95% CI: 23.66–33.18; I2 = 99.58%), 14.29% for diabetes (95% CI: 11.88–16.87; I2 = 99.10%), 12.30% for cardiovascular diseases (95% CI: 9.59–15.27; I2 = 99.33%), and 5.19% for chronic kidney disease (95% CI: 3.95–6.58; I2 = 96.42%). Conclusions We evaluated the prevalence of some of the most important comorbidities in COVID-19 patients, indicating that some underlying disorders, including hypertension, diabetes, cardiovascular diseases, and chronic kidney disease, can be considered as risk factors for patients with COVID-19 infection. Furthermore, the results show that an elderly male with underlying diseases is more likely to have severe COVID-19.

Background: The mouth cavity hosts various types of anaerobic bacteria including Porphyromonas gingivalis, which causes periodontal inflammatory diseases. P. gingivalis is a gram-negative oral anaerobe and is considered as a main etiological factor in periodontal diseases. Several studies have reported a relationship between P. gingivalis in individuals with periodontal diseases and a critical role of this bacterium in the pathogenesis of periodontal diseases. The present study aimed at estimating this probability using a meta-analysis.Methods: We searched several databases including PubMed, Scopus, Google Scholar, and Web of Science to identify case-control studies addressing the relationship between P. gingivalis with periodontal diseases. A total of 49 reports published from different countries from 1993 to 2014 were included in this study. I² (heterogeneity index) statistics were calculated to examine heterogeneity. Data were analyzed using STATA Version 11.Results: After a detailed analysis of the selected articles, 49 case-control studies with 5924 individuals fulfilled the inclusion criteria for the meta-analysis. The healthy controls included 2600 healthy individuals with a Mean±SD age of 36.56±7.45 years. The periodontal diseases group included 3356 patients with a mean age of 43.62±8.35 years. There was a statistically significant difference between P. gingivalis in periodontal patients and healthy controls; 9.24 (95% CI: 5.78 to 14.77; P = 0.000). In the other word, there was a significant relationship between the presence of P. gingivalis and periodontal diseases.Conclusion: Analyzing the results of the present study, we found a strong association between the presence of P. gingivalis and periodontal diseases. This result suggests that another research is needed to further assess this subject.

Breast cancer is the most common cancer type. In several studies, hints have been provided that there is a correlation between selenium deficiency and the incidence of breast cancer. Findings of these published reports are, however, inconsistent. This study serves as a pioneering study aiming at combining the results of studies using a meta-analytic method. A total of 16 articles published between 1980 and 2012 worldwide were selected through searching PubMed, Scopus, and Google scholar databases, and the information were analyzed using a meta-analytic method [random effects model]. I (2) statistics were used to examine heterogeneity. The information was then analyzed by STATA version 12. In this study, due to the non-uniform methods used to measure selenium concentrations, selenium levels were measured in the various subgroups in both case and control groups. There were significant correlations between selenium concentration and breast cancer [P<0.05]. Hence, the mean risk differentiating criteria were estimated to be 0.63 [95% confidence interval [95% CI] 0.93 to 0.32] in serum and toenails. Subgroup analysis showed that the value in toenails was -0.07 [95% CI -0.16 to 0.03] and in serum -1.04 [95% CI 1.71 to -0.38]. In studies in which selenium concentrations were measured in serum, a significant correlation was observed between selenium concentration and breast cancer. In contrast, in studies in which selenium concentration was measured in toenails, the correlation was not significant. Therefore, the selenium concentration can be used as one predictor for breast cancer.

BackgroundAtrial and ventricular cardiac arrhythmias are one of the most common early complications after cardiac surgery and these serve as a major cause of mortality and morbidity after cardiac revascularization. We want to evaluate the effect of magnesium sulfate administration on the incidence of cardiac arrhythmias after cardiac revascularization by doing this systematic review and meta-analysis.MethodsThe search performed in several databases (SID, Magiran, IranDoc, IranMedex, MedLib, PubMed, EmBase, Web of Science, Scopus, the Cochrane Library and Google Scholar) for published Randomized controlled trials before December 2017 that have reported the association between Magnesium consumption and the incidence of cardiac arrhythmias. This relationship measured using odds ratios (ORs) with a confidence interval of 95% (CIs). Funnel plots and Egger test used to examine publication bias. STATA (version 11.1) used for all analyses.ResultsTwenty-two studies selected as eligible for this research and included in the final analysis. The total rate of ventricular arrhythmia was lower in the group receiving magnesium sulfate than placebo (11.88% versus 24.24%). The same trend obtained for the total incidence of supraventricular arrhythmia (10.36% in the magnesium versus 23.91% in the placebo group). In general the present meta-analysis showed that magnesium could decrease ventricular and supraventricular arrhythmias compared with placebo (OR = 0.32, 95% CI 0.16–0.49; p < 0.001 and OR = 0.42, 95% CI 0.22–0.65; p < 0.001, respectively). Subgroup analysis showed that the effect of magnesium on the incidence of cardiac arrhythmias was not affected by clinical settings and dosage of magnesium. Meta-regression analysis also showed that there was no significant association between the reduction of ventricular arrhythmias and sample size.ConclusionThe results of this meta-analysis study suggest that magnesium sulfate can be used safely and effectively and is a cost-effective way in the prevention of many of ventricular and supraventricular arrhythmias.

BackgroundPremature birth is a primary cause of infant mortality and its etiology varies in different countries. Chlamydia trachomatis (CT) is a common infectious agent transmitted through sexual contact. The purpose of this study is to investigate the connection between CT infections and preterm birth by meta-analysis.MethodsAll articles published in literature databases including Google Scholar, PubMed, ISI (Web of Science), Biological Abs, IranMedex, SID, and Scopus were investigated. Twenty-four relevant articles, authored betweenm 1998–2014 were analyzed through a random effects model. Heterogeneity of the studies was evaluated by I2 index. The relationship between years of data collection, sample size, and CT infections with preterm delivery prevalence was examined by meta-regression. Data were analyzed with R and STATA [Ver. 12].ResultsThe overall prevalence of CT infections leading to preterm deliveries was estimated to be 0.13% (CI 95%: 0.11–0.16). The prevalence of CT infections leading to preterm deliveries were calculated based on the study method including PCR [0.06 (CI 95%: 0.04–0.09)], serology [0.23 (CI 95%: 0.10–0.35)] and culture [0.17 (CI 95%: 0.10–0.24)]. Analysis indicates that women with chlamydia infections were 2.28 more likely to deliver pre-term in comparison with those who were not infected. It can be concluded that chlamydia infections increase the risks of preterm delivery, OR = 2.28 (95% CI:1.64–3.16).ConclusionsIn regard to the results in numerous studies performed on different continents, this meta- analysis showed a clear association between preterm delivery and prior CT colonization.Electronic supplementary materialThe online version of this article (10.1186/s12884-018-1868-0) contains supplementary material, which is available to authorized users.

It seems that Porphyromanas gingivalis is carcinogenic, because it activates a number of inflammatory immune responses in the host and causes disorders in bacterial clearance mechanisms. There is little information on the prevalence of this bacterium in cancer patients. The aim of this study was to evaluate and compare the prevalence of P. gingivalis in cancer patients by meta-analysis methods.Different databases including PubMed, EMBASE, the Cochrane Library, Scopus, and ISI web of Knowledge were investigated and eight relevant articles published in 2000-2013 were finally analyzed. Data were analyzed by metaanalysis method, fixed effect model. I² statistics were calculated to examine the heterogeneity of papers. The information was analyzed by R and STATA Ver 12.2.A total of 711 people infected with P. gingivalis were included in this study. In total, the prevalence of P. gingivalis was 40.7% (95% CI, 19.3-62.1). The prevalence of P. gingivalis was evaluated in four case-control studies. The results of this study showed that P. gingivalis increased the chance of cancer development and periodontal disease as much as 1.36 times (OR, 1.36; 95%CI, 0.47-3.97).Although there was no significant correlation between P. gingivalis and cancer, this bacterium increased the chance of cancer and periodontal disease and could be considered as a main potential risk factor.

Malnutrition is one of the most important health issues in developing countries, which might have adverse effects on the physical and intellectual health of children. The search process was started to find Persian and English articles published until September 2017 regarding the prevalence of malnutrition in children under the age of six in Iran using national and international databases including SID, Magiran, Irandoc, IranMedex, PubMed, Medline, Scopus, and ISI Web of Science. The data were analyzed using meta-analysis methods and the random effects model. The heterogeneity of studies was analyzed using the I 2 index. The data were analyzed using R and STATA software (ver. 11.2). Twenty seven articles conducted from 2002 to 2016 were collected to be included in the meta-analysis process. The total sample size was 161,941 patients in an age range of 0-6 years. The final estimate of the prevalence of different forms of malnutrition through meta-analysis of data extracted from studies in Iran was as follows: severe underweight (1%; 95% confidence interval [CI], 1–1), moderate underweight (6%; 95% CI, 5–7), mild underweight (25%; 95% CI, 21–28), severe short stature (3%; 95% CI, 2–3), moderate short stature (8%; 95% CI, 6–9), mild short stature (21%; 95% CI, 17–24), severe slimness (1%; 95% CI, 1–1), moderate slimness (5%; 95% CI, 4–5) and mild slimness (20%; 95% CI, 17–24). Considering that the prevalence of malnutrition is relatively high in Iran, health authorities should plan to improve the nutritional status of children.