Retrospective Cohort Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Jun 15, 2021; 12(6): 868-882
Published online Jun 15, 2021. doi: 10.4239/wjd.v12.i6.868
Estimated impact of introduction of new diagnostic criteria for gestational diabetes mellitus
Leon de Wit, Anna B Zijlmans, Doortje Rademaker, Christiana A Naaktgeboren, J Hans DeVries, Arie Franx, Rebecca C Painter, Bas B van Rijn
Leon de Wit, Department of Obstetrics and Gynaecology, University Medical Center Utrecht, Utrecht 3584 EA, Netherlands
Anna B Zijlmans, Department of Obstetrics and Gynaecology, Gelderse Vallei Hospital, Ede 6716 RP, Netherlands
Doortje Rademaker, Department of Obstetrics and Gynaecology, Amsterdam University Medical Centers- Location AMC, Amsterdam 1105 AZ, Netherlands
Christiana A Naaktgeboren, Rebecca C Painter, Department of Obstetrics and Gynaecology, Amsterdam University Medical Centers–Location AMC, Amsterdam 1105 AZ, Netherlands
J Hans DeVries, Department of Endocrinology, Amsterdam University Medical Centers–Location AMC, Amsterdam 1105 AZ, Netherlands
Arie Franx, Bas B van Rijn, Department of Obstetrics and Fetal Medicine, Erasmus MC Sophia Children Hospital, Rotterdam 3015 GD, Netherlands
Author contributions: van Rijn BB contributed to the conception of the study and is the guarantor for the contents of the article, and as such, had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the analyses performed; de Wit L and Zijlmans AB collected the data, performed the analyses, drafted the manuscript and coordinated revisions; Statistical support was provided by Naaktgeboren CA; All authors have contributed to the design of the study, performed interpretation of the data and critical revision of the article for important intellectual content and approved the final version of the manuscript for publication.
Institutional review board statement: This study was exempt from approval of the Medical Research Ethics Committee of the University Medical Center Utrecht (reference number 16-711/C), which granted a waiver after reviewing the protocol because the Dutch Medical Research Involving Human Subjects Act (WMO) did not apply to this study.
Informed consent statement: With this document we would like to inform you that for the manuscript regarding our study entitled ’Estimated impact of introduction of new diagnostic criteria for gestational diabetes mellitus’ no individual informed consent forms have been signed by participants as approved by our Institutional Review Board (MREC of the University Medical Center Utrecht). See the attached Institutional Review Board Approval Form.
Conflict-of-interest statement: The authors declare that there is no duality of interest associated with this manuscript.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Bas B van Rijn, MD, MSc, PhD, Assistant Professor, Department of Obstetrics and Fetal Medicine, Erasmus MC Sophia Children Hospital, Doctor Molewaterplein 40, Rotterdam 3015 GD, Netherlands. b.vanrijn@erasmusmc.nl
Received: February 2, 2021
Peer-review started: February 2, 2021
First decision: February 25, 2021
Revised: March 12, 2021
Accepted: April 25, 2021
Article in press: April 25, 2021
Published online: June 15, 2021
Processing time: 122 Days and 0.2 Hours
ARTICLE HIGHLIGHTS
Research background

Gestational diabetes mellitus (GDM) is the most common metabolic disorder of pregnancy. It is associated with both short- and long-term fetal, neonatal and maternal complications. Treatment of GDM has been shown to improve pregnancy outcomes.

Research motivation

Worldwide different diagnostic criteria to diagnose GDM are being used. Recently the Hyperglycemia and Adverse Pregnancy Outcome study has shown that maternal glucose levels below the most used thresholds increase the risk of adverse outcomes. As a result, new diagnostic criteria have been proposed by the World Health Organization (WHO) in 2013. These new, more stringent criteria have been shown to greatly affect the number of women diagnosed with GDM, which in turn can have great consequences for health care costs and effectiveness of current treatment strategies. However, the effects vary in different populations and are influenced by patient characteristics such as ethnicity and maternal body mass index.

Research objectives

We aimed to estimate the impact of the WHO 2013 criteria, compared with the WHO 1999 criteria, on the incidence of gestational diabetes mellitus as well as to determine the diagnostic accuracy for detecting adverse pregnancy outcomes. We sought to evaluate the patient characteristics and pregnancy outcomes of women with a discordant diagnosis specifically, as these are of importance for the treatment effects that may be expected. Currently, the treatment effects in these women are unknown.

Research methods

For this study we evaluated a cohort of 3338 women that were tested for GDM using a 75 g oral glucose tolerance test in the University Medical Center Utrecht. We applied both the current WHO 1999 criteria and the newly proposed WHO 2013 criteria for GDM. We determined the change in the number of GDM diagnoses. Also, we separately reported on patient characteristics and pregnancy outcomes of women with discordant diagnoses and compared these to the non-GDM women. Lastly, we determined the likelihood ratios for adverse outcomes for the different groups.

Research results

Retrospectively applying the WHO 2013 criteria increased the cohort incidence by 13.1%, from 19.3 to 32.4%. Discordant diagnoses occurred in 21.3%; 4.1% would no longer be labelled as GDM, and 17.2% were newly diagnosed. Compared to the non-GDM group, women newly diagnosed were older, had higher rates of obesity, higher diastolic blood pressure and higher rates of caesarean deliveries. Their infants were more often delivered preterm, large-for-gestational-age and were at higher risk of a 5-min Apgar score < 7. Women excluded from GDM were older and had similar pregnancy outcomes compared to the non-GDM group, except for higher rates of shoulder dystocia (4.3% vs 1.3%, P = 0.015). Positive likelihood ratios for adverse outcomes in all groups were generally low, ranging from 0.54 to 2.95.

Research conclusions

The number of women diagnosed with GDM increases substantially with the WHO 2013 compared to the WHO 1999 criteria. Women additionally diagnosed are at increased risk for adverse pregnancy outcomes. However, they seem to be at lower risk than women who would be diagnosed with GDM by both the old and new criteria. Also, likelihood ratios for adverse outcomes comparing both diagnostic criteria are generally low. Treatment effects may therefore be lower in newly diagnosed women, which may result in overtreatment of women newly diagnosed with GDM according to the WHO 2013 criteria.

Research perspectives

Adopting the WHO 2013 criteria results in an increased number of women diagnosed with GDM and translates to an excess risk of adverse pregnancy outcomes, supporting the need for intervention studies to estimate the treatment benefit and cost-effectiveness to improve clinically relevant outcomes for these previously untreated pregnant women.