Impact of Pre-Pregnancy Hemoglobin Level on the Association Between Pre-Pregnancy Body Mass Index and Gestational Diabetes Mellitus: A Retrospective Cohort Study in a Single Center in China

Abstract

Aim

To assess the impact of maternal pre-pregnancy body mass index (BMI) on gestational diabetes mellitus (GDM) based on different pre-pregnancy hemoglobin levels.

Methods

This retrospective cohort study included 1289 pregnant women between June 2020 and January 2022. Clinical data were collected by reviewing their medical and antepartum screening records between 24 and 28 gestational weeks, including pre-pregnancy BMI and pre-pregnancy hemoglobin (Hb) levels. The diagnosis of GDM mainly depended on oral glucose tolerance test (OGTT) during 24–28 weeks. Restricted cubic spline (RCS) was used to investigate the association between the pre-pregnancy Hb level and the risk of GDM. Univariate and multivariate logistic regression analyses were applied to evaluate the relative risk of GDM.

Results

Of the 1289 included pregnant women, 187 (14.5%) women were diagnosed with GDM in this study. The pre-pregnancy Hb level was significantly associated with GDM risk, and the pre-pregnancy Hb level of 123 g/L was identified as the threshold to stratify and assess the association between the GDM risk and the pre-pregnancy BMI. For women with a pre-pregnancy Hb level ≥123 g/L, the pre-pregnancy BMI showed a significant association with GDM risk, and the estimated incidence rate of GDM was 7.7%, 14.8%, 36.3% and 44% for underweight, normal-weight, overweight and obese pregnant women, respectively. After adjusting for potential influencing factors of GDM, the respective relative risk was 1.0 (reference), 2.04 (95% CI 0.84, 4.99), 7.06 (2.66, 18.61), and 10.77 (2.85, 40.63) (P for trend < 0.001).

Conclusion

In pregnant women with a pre-pregnancy Hb level ≥123 g/L, pre-pregnancy BMI showed a more significant association with GDM risk as compared with those with a pre-pregnancy Hb level <123 g/L.

Keywords:

• pregnancy
• body mass index
• hemoglobin
• gestational diabetes mellitus
• overweight
• obese

Abbreviations

GDM, Gestational diabetes mellitus; BMI, body mass index; Hb, hemoglobin.

Data Sharing Statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Shanghai Pudong Hospital with the code (WZ-14).

Acknowledgments

We would like to thank Shou-fei Yang (Shanghai Municipal Center for Disease Control & Prevention) for conducting statistical analysis. Kui Wu and Hui-Hui Ke are co-first authors for this study.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors have nothing to declare for this work.

Additional information

Funding

This work was supported by the Project of Key Medical Specialty and Treatment Center of Pudong Hospital of Fudan University. (Grant No. Zdzk2020-17).