BackgroundInvestigating the association between caesarean section (SC) and childhood asthma has shown contradictory results in different studies. The present study was conducted to determine the association between SC and childhood asthma.Material and methodThe present study was conducted based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. All the steps of the study were conducted independently by two reviewers from the inception until February 1, 2019. In case of disagreement, the third reviewer resolved it. We searched international online databases, including Scopus, Cochrane Library, PubMed/Medline, Embase, Web of Science (ISI), Science Direct, and Google scholar. The results of studies were combined using random effects model, and heterogeneity was measured through I2 index and Cochran’s Q test. Comprehensive Meta-Analysis Software was used for meta-analysis. The significance level of all tests was considered to be P < 0.05.ResultsThe heterogeneity rate was high (I2 = 67.31%, P < 0.001) in 37 studies. The results showed that SC increased the risk of childhood asthma (RR (relative risk) = 1.20 [95% CI 1.15–1.25, P < 0.001]). The association between emergency and elective SC and childhood asthma was significant with RR of 1.18 (95% CI 1.07–1.29, P < 0.001) in 13 studies and 1.23 (95% CI 1.20–1.26, P < 0.001) in 13 studies, respectively. The subgroup analysis for RR of childhood asthma in SC indicated that study design (P = 0.306), prospective/retrospective studies (P = 0.470), quality of studies (P = 0.514), continent (P = 0.757), age of diagnosis (P = 0.283) and year of publication (P = 0.185) were not effective in the heterogeneity of studies. Sensitivity analysis by removing one study at a time indicated that the overall estimate is robust.ConclusionAccording to the meta-analysis, SC (overall, elective, and emergency) increased the risk of childhood asthma. Therefore, it is hoped that developing clinical guidelines and implementing appropriate management plans would diminish the risk of asthma.

Chronic gastritis accompanied with H. pylori infection was revealed as the most prevalent variable among dyspeptic patients. Also, higher BMI compared to normal and smokers compared to non-smokers were more involved by precancerous lesions.

Placenta membranacea is one of the most barley anomalies happens in pregnancy defined by chorionic villi (partially or completely) covered the fetus membrane. Autosomal recessive polycystic kidney disease in fetus is also a rare case with an incidence of 1: 20,000 live births resulting in a 30% death rate in neonates. In this case for the first time, we reported a placenta membranacea and autosomal recessive polycystic kidney disease occurred with together. A 25-year-old woman was admitted at 16 weeks of gestation for inducing abortion with autosomal recessive polycystic kidney disease in fetus diagnosed in routine sonography fellowship. Postdelivery examination revealed a placenta totally enveloped the fetus, oligohydramnious and bilateral enlarged polycystic kidneys of fetus. Histological study indicated umbilicus has only one artery and one vein as well as autosomal recessive polycystic kidney disease and directly attachment of chorionic villi to fetal membrane eventually diagnosed as complete placenta membranacea. The etiology of placenta membranacea is not completely clarified. As autosomal recessive polycystic kidney disease is a result of mutation in PKHD1 gene, so our finding may be initiates a new investigation about genetic relation between placenta membranacea and autosomal recessive polycystic kidney disease.