63 research outputs found
Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis
BACKGROUND:
Fetal macrosomia is associated with an increased risk of adverse maternal and neonatal outcomes.
OBJECTIVES:
To compare the accuracy of antenatal two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, and magnetic resonance imaging (MRI) in predicting fetal macrosomia at birth.
SEARCH STRATEGY:
Medline (1966-2013), Embase, the Cochrane Library and Web of Knowledge.
SELECTION CRITERIA:
Cohort or diagnostic accuracy studies of women with a singleton pregnancy, who had third-trimester imaging to predict macrosomia (>4000 g, >4500 g or >90th or >95th centile).
DATA COLLECTION AND ANALYSIS:
Two reviewers screened studies, performed data extraction and assessed methodological quality. The bivariate model was used to obtain summary sensitivities, specificities and likelihood ratios.
MAIN RESULTS:
Fifty-eight studies (34 367 pregnant women) were included. Most were poorly reported. Only one study assessed 3D ultrasound volumetry. For predicting birthweight >4000 g or >90th centile, the summary sensitivity for 2D ultrasound (Hadlock) estimated fetal weight (EFW) >90th centile or >4000 g (29 studies) was 0.56 (95% CI 0.49-0.61), 2D ultrasound abdominal circumference (AC) >35 cm (four studies) was 0.80 (95% confidence interval [95% CI] 0.69-0.87) and MRI EFW (three studies) was 0.93 (95% CI 0.76-0.98). The summary specificities were 0.92 (95% CI 0.90-0.94), 0.86 (95% CI 0.74-0.93) and 0.95 (95% CI 0.92-0.97), respectively.
CONCLUSION:
There is insufficient evidence to conclude that MRI EFW is more sensitive than 2D ultrasound AC (which is more sensitive than 2D EFW); although it was more specific. Further primary research is required before recommending MRI EFW for use in clinical practice
Maternal position in the second stage of labour for women with epidural anaesthesia
© 2018 The Cochrane Collaboration. Background: Epidural analgesia in labour prolongs the second stage and increases instrumental delivery. It has been suggested that a more upright maternal position during all or part of the second stage may counteract these adverse effects. This is an update of a Cochrane Review published in 2017. Objectives: To assess the effects of different birthing positions (upright or recumbent) during the second stage of labour, on maternal and fetal outcomes for women with epidural analgesia. Search methods: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (5 June 2018), and the reference lists of retrieved studies. Selection criteria: All randomised or quasi-randomised trials including pregnant women (primigravidae or multigravidae) in the second stage of induced or spontaneous labour receiving epidural analgesia of any kind. Cluster-randomised controlled trials would have been eligible for inclusion but we found none. Studies published in abstract form only were also eligible. We assumed the experimental intervention to be maternal use of any upright position during the second stage of labour, compared with the control condition of remaining in any recumbent position. Data collection and analysis: Two review authors independently assessed trials for inclusion, assessed risks of bias, and extracted data. We contacted study authors to obtain missing data. We assessed the quality of the evidence using the GRADE approach. We carried out a planned sensitivity analysis of the three studies with low risks of bias for allocation concealment and incomplete outcome data reporting, and further excluded one study with a co-intervention (this was not prespecified). Main results: We include eight randomised controlled trials, involving 4464 women, comparing upright positions versus recumbent positions in this update. Five were conducted in the UK, one in France and two in Spain. The largest UK trial accounted for three-quarters of all review participants, and we judged it to have low risk of bias. We assessed two other trials as being at low risk of selection and attrition bias. We rated four studies at unclear or high risk of bias for both selection and attrition bias and one study as high risk of bias due to a co-intervention. The trials varied in their comparators, with five studies comparing different positions (upright and recumbent), two comparing ambulation with (recumbent) non-ambulation, and one study comparing postural changes guided by a physiotherapist to a recumbent position. Overall, there may be little or no difference between upright and recumbent positions for our combined primary outcome of operative birth (caesarean or instrumental vaginal): average risk ratio (RR) 0.86, 95% confidence interval (CI) 0.70 to 1.07; 8 trials, 4316 women; I 2 = 78%; low-quality evidence. It is uncertain whether the upright position has any impact on caesarean section (RR 0.94, 95% CI 0.61 to 1.46; 8 trials, 4316 women; I 2 = 47%; very low-quality evidence), instrumental vaginal birth (RR 0.90, 95% CI 0.72 to 1.12; 8 trials, 4316 women; I 2 = 69%) and the duration of the second stage of labour (mean difference (MD) 6.00 minutes, 95% CI -37.46 to 49.46; 3 trials, 456 women; I 2 = 96%), because we rated the quality of the evidence as very low for these outcomes. Maternal position in the second stage of labour probably makes little or no difference to postpartum haemorrhage (PPH), (PPH requiring blood transfusion): RR 1.20, 95% CI 0.83 to 1.72; 1 trial, 3093 women; moderate-quality evidence. Maternal satisfaction with the overall childbirth experience was slightly lower in the upright group: RR 0.95, 95% CI 0.92 to 0.99; 1 trial, 2373 women. Fewer babies were born with low cord pH in the upright group: RR 0.43, 95% CI 0.20 to 0.90; 2 trials, 3159 infants; moderate-quality evidence. The results were less clear for other maternal or fetal outcomes, including trauma to the birth canal requiring suturing (average RR 1.00, 95% CI 0.89 to 1.13; 3 trials, 3266 women; I 2 = 46%; low-quality evidence), abnormal fetal heart patterns requiring intervention (RR 1.69, 95% CI 0.32 to 8.84; 1 trial, 107 women; very low-quality evidence), or admission to neonatal intensive care unit (RR 0.54, 95% CI 0.02 to 12.73; 1 trial, 66 infants; very low-quality evidence). However, the CIs around some of these estimates were wide, and we cannot rule out clinically important effects. In our sensitivity analysis of studies at low risk of bias, upright positions increase the chance of women having an operative birth: RR 1.11, 95% CI 1.03 to 1.20; 3 trials, 3609 women; high-quality evidence. In absolute terms, this equates to 63 more operative births per 1000 women (from 17 more to 115 more). This increase appears to be due to the increase in caesarean section in the upright group (RR 1.29; 95% CI 1.05 to 1.57; 3 trials, 3609 women; high-quality evidence), which equates to 25 more caesarean sections per 1000 women (from 4 more to 49 more). In the sensitivity analysis there was no clear impact on instrumental vaginal births: RR 1.08, 95% CI 0.91 to 1.30; 3 trials, 3609 women; low-quality evidence. Authors' conclusions: There may be little or no difference in operative birth between women who adopt recumbent or supine positions during the second stage of labour with an epidural analgesia. However, the studies are heterogeneous, probably related to differing study designs and interventions, differing adherence to the allocated intervention and possible selection and attrition bias. Sensitivity analysis of studies at low risk of bias indicated that recumbent positions may reduce the need for operative birth and caesarean section, without increasing instrumental delivery. Mothers may be more satisfied with their experience of childbirth by adopting a recumbent position. The studies in this review looked at left or right lateral and semi-recumbent positions. Recumbent positions such as flat on the back or lithotomy are not generally used due to the possibility of aorto-caval compression, although we acknowledge that these recumbent positions were not the focus of trials included in this review
Addressing social determinants of noncommunicable diseases in primary care: a systematic review
Objective
To explore how primary care organizations assess and subsequently act upon the social determinants of noncommunicable diseases in their local populations.
Methods
For this systematic review we searched the online databases of PubMed®, MEDLINE®, Embase® and the Health Management Information Consortium from inception to 28 June 2019, along with hand-searching of references. Studies of any design that examined a primary care organization assessing social determinants of noncommunicable diseases were included. For quality assessment we used Cochrane’s tool for assessing risk of bias in non-randomized studies of interventions. We used narrative data synthesis to appraise the extent to which the assessments gathered data on the domains of the World Health Organization social determinants of health framework.
Findings
We identified 666 studies of which 17 were included in the review. All studies used descriptive study designs. Clinic-based and household surveys and interviews were more commonly used to assess local social determinants than population-level data. We found no examples of organizations that assessed sociopolitical drivers of noncommunicable diseases; all focused on sociodemographic factors or circumstances of daily living. Nevertheless, the resulting actions to address social determinants ranged from individual-level interventions to population-wide measures and introducing representation of primary care organizations on system-level policy and planning committees.
Conclusion
Our findings may help policy-makers to consider suitable approaches for assessing and addressing social determinants of health in their domestic context. More rigorous observational and experimental evidence is needed to ascertain whether measuring social determinants leads to interventions which mitigate unmet social needs and reduce health disparities
Addressing social determinants of noncommunicable diseases in primary care: a systematic review.
OBJECTIVE: To explore how primary care organizations assess and subsequently act upon the social determinants of noncommunicable diseases in their local populations. METHODS: For this systematic review we searched the online databases of PubMed®, MEDLINE®, Embase® and the Health Management Information Consortium from inception to 28 June 2019, along with hand-searching of references. Studies of any design that examined a primary care organization assessing social determinants of noncommunicable diseases were included. For quality assessment we used Cochrane's tool for assessing risk of bias in non-randomized studies of interventions. We used narrative data synthesis to appraise the extent to which the assessments gathered data on the domains of the World Health Organization social determinants of health framework. FINDINGS: We identified 666 studies of which 17 were included in the review. All studies used descriptive study designs. Clinic-based and household surveys and interviews were more commonly used to assess local social determinants than population-level data. We found no examples of organizations that assessed sociopolitical drivers of noncommunicable diseases; all focused on sociodemographic factors or circumstances of daily living. Nevertheless, the resulting actions to address social determinants ranged from individual-level interventions to population-wide measures and introducing representation of primary care organizations on system-level policy and planning committees. CONCLUSION: Our findings may help policy-makers to consider suitable approaches for assessing and addressing social determinants of health in their domestic context. More rigorous observational and experimental evidence is needed to ascertain whether measuring social determinants leads to interventions which mitigate unmet social needs and reduce health disparities
The haemodynamics of the human placenta in utero
© 2020 Dellschaft et al. We have used magnetic resonance imaging (MRI) to provide important new insights into the function of the human placenta in utero. We have measured slow net flow and high net oxygenation in the placenta in vivo, which are consistent with efficient delivery of oxygen from mother to fetus. Our experimental evidence substantiates previous hypotheses on the effects of spiral artery remodelling in utero and also indicates rapid venous drainage from the placenta, which is important because this outflow has been largely neglected in the past. Furthermore, beyond Braxton Hicks contractions, which involve the entire uterus, we have identified a new physiological phenomenon, the 'utero-placental pump', by which the placenta and underlying uterine wall contract independently of the rest of the uterus, expelling maternal blood from the intervillous space
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