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Notes: A substantive amendment to this systematic review was last made on 25 June 1999. Cochrane reviews are regularly checked and updated if necessary. 〈section xml:id="abs1-1"〉〈title type="main"〉ABSTRACT Background: Early amniotomy has been advocated as a component of the active management of labour. Several randomised trials comparing routine amniotomy to an attempt to conserve the membranes have been published. Their limited sample sizes limit their ability to address the effects of amniotomy on indicators of maternal and neonatal morbidity. Objectives: To study the effects of amniotomy on the rate of Cesarean delivery and on other indicators of maternal and neonatal morbidity (Apgar less than 7 at 5 minutes, admission to NICU). Search strategy: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. Selection criteria: All acceptably controlled trials of amniotomy during first stage of labour were eligible. Data collection and analysis: Data were extracted by two trained reviewers from published reports. Trials were assigned methodological quality scores based on a standardised rating system. Typical odds ratios (ORs) were calculated using Peto's method. Main results: Amniotomy was associated with a reduction in labour duration of between 60 and 120 minutes. There was a marked trend toward an increase in the risk of Cesarean delivery: OR = 1.26; 95% Confidence Interval (CI) = 0.96–1.66. The likelihood of a 5-minute Apgar score less than 7 was reduced in association with early amniotomy (OR = 0.54; 95% CI = 0.30–0.96). Groups were similar with respect to other indicators of neonatal status (arterial cord pH, NICU admissions). There was a statistically significant association of amniotomy with a decrease in the use of oxytocin: OR = 0.79; 95% CI = 0.67–0.92. Reviewers' conclusions: Routine early amniotomy is associated with both benefits and risks. Benefits include a reduction in labour duration and a possible reduction in abnormal 5-minute Apgar scores. The meta-analysis provides no support for the hypothesis that routine early amniotomy reduces the risk of Cesarean delivery. Indeed there is a trend toward an increase in Cesarean section. An association between early amniotomy and Cesarean delivery for fetal distress is noted in one large trial. This suggests that amniotomy should be reserved for women with abnormal labour progress. Citation: Fraser WD, Turcot L, Krauss I, Brisson-Carrol G. Amniotomy for shortening spontaneous labour (Cochrane Review). In: The Cochrane Library, 1, 2001. Oxford: Update Software. MeSH: Amnion/*surgery; Cesarean Section; Female; Human; *Labor; Labor Complications/*prevention & control; Pregnancy The preceding reports are abstracts of regularly updated, systematic reviews prepared and maintained by the Cochrane Collaboration. The full text of the reviews are available in The Cochrane Library (ISSN 1464-780X). The Cochrane Library is prepared and published by Update Software Ltd. All rights reserved. See www.update-software.com or contact Update Software, info@update.co.uk, for information on subscribing to The Cochrane Library in your area. Update Software Ltd, Summertown Pavilion, Middle Way, Oxford OX2 7LG, United Kingdom. (Tel: +44 1865 513902; Fax: +44 1865 516918).

Notes: Correlation coefficients measuring the historical relationships of returns on commercial property and both equities and conventional gilts appear to be low. Conversely, the correlation between gilts and equities appears to be relatively high. This implies that property provides diversification benefits to a mixed asset portfolio dominated by equities and gilts. However, there is some debate as to the reliability of these correlations and property's diversification benefits. In this paper we use Granger causality tests and cointegration techniques to demonstrate that there is no long-run relationship between property returns and those of either gilts or equities. This confirms the diversification benefits of including property in a mixed asset portfolio.