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The objective of this study is to assess and quantify the risk for gestational diabetes mellitus (GDM) according to prepregnancy maternal body mass index (BMI). The design is a systematic review of observational studies published in the last 30 years. Four electronic databases were searched for publications (1977-2007). BMI was elected as the only measure of obesity, and all diagnostic criteria for GDM were accepted. Studies with selective screening for GDM were excluded. There were no language restrictions. The methodological quality of primary studies was assessed. Some 1745 citations were screened, and 70 studies (two unpublished) involving 671 945 women were included (59 cohorts and 11 case-controls). Most studies were of high or medium quality. Compared with women with a normal BMI, the unadjusted pooled odds ratio (OR) of an underweight woman developing GDM was 0.75 (95% confidence interval [CI] 0.69 to 0.82). The OR for overweight, moderately obese and morbidly obese women were 1.97 (95% CI 1.77 to 2.19), 3.01 (95% CI 2.34 to 3.87) and 5.55 (95% CI 4.27 to 7.21) respectively. For every 1 kg m(-2) increase in BMI, the prevalence of GDM increased by 0.92% (95% CI 0.73 to 1.10). The risk of GDM is positively associated with prepregnancy BMI. This information is important when counselling women planning a pregnancy.

The whole findings of this systematic review are no more than suggestive of the superiority of early over late tracheostomy because no information of high quality is available for specific subgroups with particular characteristics.

Background Subclinical hypothyroidism is defined as an elevated serum thyroid-stimulating hormone (TSH) level with normal free thyroid hormones values. The prevalence of subclinical hypothyroidism is 4% to 8% in the general population, and up to 15% to 18% in women who are over 60 years of age. There is considerable controversy regarding the morbidity, the clinical significance of subclinical hypothyroidism and if these patients should be treated. Objectives To assess the effects of thyroid hormone replacement for subclinical hypothyroidism. Search methods We searched The Cochrane Library, MEDLINE, EMBASE and LILACS. Ongoing trials databases, reference lists and abstracts of congresses were scrutinized as well. Selection criteria All studies had to be randomised controlled trials comparing thyroid hormone replacement with placebo or no treatment in adults with subclinical hypothyroidism. Minimum duration of follow-up was one month. Data collection and analysis Two authors independently assessed trial quality and extracted data. We contacted study authors for missing or additional information. Main results Twelve trials of six to 14 months duration involving 350 people were included. Eleven trials investigated levothyroxine replacement with placebo, one study compared levothyroxine replacement with no treatment. We did not identify any trial that assessed (cardiovascular) mortality or morbidity. Seven studies evaluated symptoms, mood and quality of life with no statistically significant improvement. One study showed a statistically significant improvement in cognitive function. Six studies assessed serum lipids, there was a trend for reduction in some parameters following levothyroxine replacement. Some echocardiographic parameters improved after levothyroxine replacement therapy, like myocardial relaxation, as indicated by a significant prolongation of the isovolumic relaxation time as well as diastolic dysfunction. Only four studies reported adverse events with no statistically significant differences between groups.

Background:  Sublingual immunotherapy (SLIT) is effective and safe in the treatment of allergic rhinitis. However, there is no meta‐analysis in asthma treatment. Methods:  The clinical efficacy of SLIT for asthma was evaluated through a systematic review with meta‐analysis. MEDLINE (1966–2005), EMBASE (1974–2005), LILACS (1982–2005), and the Cochrane Library were searched for related literature in any language. Randomized‐controlled clinical trials (RCT) on SLIT in asthma treatment for adults and children were selected. From 119 citations, 25 studies with 1706 patients were included in this meta‐analysis. For each report, quality scores were assigned and data were extracted in relation to the outcomes analyzed: asthmatic symptoms, use of asthma medications, lung function, and bronchial provocation. Results:  According to the Jadad quality method, 64% of the studies were assigned scores of 4 or 5. Immunotherapy was seen to significantly reduce asthma severity when parameter compositions were all analyzed by categorical outcomes. There was a nonsignificant reduction in asthma symptoms when analyzed using standardized mean differences. No severe reactions were observed. Conclusions:  This meta‐analysis found that SLIT is beneficial for asthma treatment albeit the magnitude of the effect is not very large. Moreover, it is a safe alternative to the subcutaneous route. More RCT with standardization of symptom scores and medications are needed in order to contribute further to this subject.

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Background Calcium supplementation during pregnancy may reduce the risk of hypertensive disorders of pregnancy. Search strategy We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Central Register of Controlled Trials (March 2006).Selection criteria Randomised trials comparing at least 1 g of calcium daily during pregnancy with placebo. Eligibility and trial quality were assessed.Data collection and analysis Data were extracted and analysed using Review Manager software.Main results Twelve studies (15 528 women) were included, all of good quality. Most women were at low risk and had low dietary calcium. High blood pressure was reduced with calcium supplementation rather than placebo (11 trials, 14 946 women: relative risk [RR] random effects model 0.70; 95% CI 0.57-0.86), as was pre-eclampsia (12 trials, 15 206 women: RR 0.48; 95% CI 0.33-0.69). The effect was greatest for women at high risk (five trials, 587 women: RR 0.22; 95% CI 0.12-0.42) and for those with low baseline calcium intake (seven trials, 10 154 women: RR 0.36; 95% CI 0.18-0.70). There was heterogeneity, with less effect in the larger trials. The composite outcome maternal death or serious morbidity was reduced (four trials, 9732 women: RR 0.80; 95% CI 0.65-0.97). The syndrome of haemolysis, elevated liver enzymes and low platelets was increased (two trials, 12 901 women: RR 2.67; 95% CI 1.05-6.82). There was no overall effect on the risk of preterm birth or stillbirth or death before discharge from hospital.Conclusions Calcium supplementation appears to reduce the risk of pre-eclampsia and to reduce the rare occurrence of the composite outcome 'maternal death or serious morbidity'. There were no other clear benefits or harms.Commentary We present the hypothesis that adequate dietary calcium before and in early pregnancy may be needed to prevent the underlying pathology responsible for pre-eclampsia. We suggest that the research agenda be redirected towards calcium supplementation at a community level.

New citation: conclusions changed We include seven new studies in our review update. We have excluded 15 previously-included studies from the update. Our conclusions now include strength-of-evidence recommendations and have been updated. 30 October 2018 Updated A new review team has updated this review and metaanalysis. We compared non-invasive positive pressure ventilation to standard medical care for acute cardiogenic pulmonary oedema. Our inclusion criteria have been updated and we include RCTs only. We performed our updated literature search from database inception to 20 September 2018. We identified new articles for inclusion and have fully revised this systematic review. History 0416 Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema