The use of clinical guidelines is likely to have a positive influence on the management of diabetes during pregnancy
[
1,
11]. This article provides an overview of the quality and content of clinical guidelines regarding the management of diabetes during pregnancy. We reviewed eight guidelines from six different countries. This study shows that the overall quality of these guidelines was low when using the AGREE instrument. Only two guidelines were found to be of moderate
[
30] or high quality
[
31]. In general, the recommendations in several domains were similar except for screening for GDM and induction for delivery at term.
It is important that guidelines are of high quality. According to the AGREE instrument, most guidelines inadequately reported on editorial independence, stakeholder involvement and rigour of development. Especially the low score on rigour of development is concerning, because explicit descriptions of how the available evidence was identified and selected is essential for the development of valid and reliable evidence-based recommendations.
Also descriptions of the updating procedures of the guidelines were poor, although it is important to keep the recommendations based on the best available evidence. Regarding stakeholder involvement, it might be important that views and preferences of patients are taken under consideration and that guidelines are piloted among target groups. This may increase success of implementation and thereby improve the management of diabetes during pregnancy.
The low quality of most guidelines could be explained by the fact that the AGREE instrument was not used by the committees that were developing or updating the guidelines. Only the committee of the NICE guideline
[
31] used an instrument to asses the quality which is part of their rigorous, standardized procedures. The use of the AGREE instrument already showed to improve the quality of other guidelines, such as guidelines on the management of low back pain
[
14,
32].
It should be noted that the score on the AGREE instrument does not only depend on the methodological quality of the guideline, but also on the quality of reporting. It is possible that guidelines of high methodological quality score low on the AGREE instrument due to poor reporting. One should bear this in mind while interpreting the results of the current study. However, most guidelines were published years after the AGREE instrument was first published. One would assume that guideline developers are aware of the most up to date discussions and literature about quality of developing and quality of reporting guidelines.
Although there is some debate about using the AGREE instrument for assessing the quality of guidelines and about a 50% cut-off value, other papers on back pain and acute gastroenteritis have used this approach before
[
13,
14]. Obviously, if the quality criteria were stricter, then even fewer guidelines would be considered of good quality, as shown in Table

.
Regarding the recommendations, there were some discrepancies between guidelines. These differences might be a result of lack of evidence or weak associations. For example, recommendations regarding screening on GDM in the guidelines diverged as was also found in other studies
[
33,
34]. This diversity might be caused by equivocal evidence on this topic in the period in which most guidelines were developed
[
35]. Also consensus usually does not warrant similar recommendations because not only the available evidence but also other aspects such as costs, applicability, constitution of the guideline committee and ethical considerations influence recommendations.
Nonetheless, more variety between recommendations was expected because of the variety in health care systems, culture in various countries and the differences in membership of the guideline committees. Therefore, current scientific evidence on the management of diabetes seems to be appropriate to generalize conclusions to these different groups. Moreover, previous studies also showed that international guidelines were consistent in most of their recommendations, especially on preconceptive care in women with diabetes
[
36].
The similarities between the guidelines included in this study could partly be explained by the fact that they all have been developed between 2001 and 2010. Moreover, the recommendations of the ADA guideline
[
16,
17] and the CCGC guideline
[
28] were based mainly on the same literature. Also some references of the IDF guideline
[
30] were similar to those of the ADA
[
16,
17] and the NICE guideline
[
31]. In addition, the recommendations of the guideline of the DSOG
[
29] were partially based on the NICE guideline
[
31].