EAL

GDM: Abnormal Glucose Tolerance During Pregnancy (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The objective of this review was to complete a systematic review of alternative policies of care for women with gestational diabetes and impaired glucose tolerance (IGT) in pregnancy.

Inclusion Criteria:

Randomized controlled trials comparing alternative management strategies for women with gestational diabetes and IGT in pregnancy.

Exclusion Criteria:

See inclusion criteria.

Description of Study Protocol:

Recruitment

The Cochrane Pregnancy and Childbirth Group trials register (12 September 2002) was searched and the bibliographies of relevant papers. The Cochrane Central Register of Controlled Trials was also searched (The Cochrane Library, Issue 3, 2002).

Design: Systematic review

Blinding used (if applicable)

Data were extracted and checked independently by two reviewers. Any disagreements were resolved by discussion with the third reviewer.

Intervention (if applicable)

Data from eligible studies were extracted and summarized using a data extraction sheet. Where data are missing from a report, attempts were made to contact the authors to obtain the information. Two reviewers undertook data extraction. Any disagreements were resolved through discussion. The included studies were critically appraised and rated for validity according to allocation concealment, baseline comparability of groups, intent to treat analysis,and blinded outcome assessment. These were rated as A (adequate), B (unclear) and C (clearly inadequate) as suggested in the Cochrane Reviewer's Handbook (Clark 2000).

Statistical Analysis

Heterogeneity was assessed using the chi-squared test. Where study results were homogeneous and could be pooled, a statistical meta analysis was performed using a random effects model weighting each study by the inverse of its variance. Relative risks (RR) with 95% confidence intervals (CI) were calculated for maternal and fetal outcomes.

Data Collection Summary:

Timing of Measurements: Not applicable

Dependent Variables:

Maternal outcomes
Fetal outcomes

Independent Variables:

Interventions included any comparisons of management of abnormal glucose tolerance in pregnancy

Control Variables: Not applicable

Description of Actual Data Sample:

Initial N: 3 studies, 233 women

Attrition (final N): 3 studies

Age: not mentioned

Ethnicity: not mentioned

Other relevant demographics: NA

Anthropometrics

All 3 studies were relatively small, one was particularly small with a high withdrawal rate. Randomization was adequate in two of the studies and partial in the third. Allocation concealment was classified was adequate in one study and unclear in the other two. A number of outcomes are only reported by one trial and many of the outcomes are not addressed by any of the included studies.

Location: Worldwide studies

Summary of Results:

Other Findings

Three studies with 233 women were included in this review.

The difference in abdominal operative delivery rates is not statistically significant (RR 0.86, 95% CI 0.51 to 1.45) and the effect of special care baby unit admission is also not signficant (RR 0.49, 95% CI 0.19 to 1.24).

Reduction in birth weight greater than 90th centile (RR 0.55, 95% CI 0.19 to 1.61) was not found to be significant.

This review suggests that an interventionist policy of treatment may be associated with a reduced risk of neonatal hypoglycemia (RR 0.25, 95% CI 0.07 to 0.86).

No other statistically significant differences were detected.

A number of outcomes are only reported by one study resulting in a small sample and wide confidence intervals.

Author Conclusion:

There are insufficient data for any reliable conclusions about the effects of treatments for impaired glucose tolerance on perinatal outcome.

Funding Source:

Reviewer Comments:

Small number of studies.

Quality Criteria Checklist: Review Articles
Relevance Questions
	1.	Will the answer if true, have a direct bearing on the health of patients?	Yes
	2.	Is the outcome or topic something that patients/clients/population groups would care about?	Yes
	3.	Is the problem addressed in the review one that is relevant to dietetics practice?	Yes
	4.	Will the information, if true, require a change in practice?	Yes

Validity Questions
	1.	Was the question for the review clearly focused and appropriate?	Yes
	2.	Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described?	Yes
	3.	Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased?	Yes
	4.	Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible?	Yes
	5.	Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined?	Yes
	6.	Was the outcome of interest clearly indicated? Were other potential harms and benefits considered?	Yes
	7.	Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described?	Yes
	8.	Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included?	Yes
	9.	Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed?	Yes
	10.	Was bias due to the review's funding or sponsorship unlikely?	Yes