Introduction
Gestational diabetes mellitus (GDM) is a form of glucose intolerance first recognized during pregnancy, affecting a significant number of women worldwide. Its presence can complicate pregnancies and lead to adverse outcomes for both mother and child. Concurrently, body mass index (BMI) changes between pregnancies have been identified as a critical factor influencing maternal health and pregnancy outcomes. This retrospective cohort study explores the economic implications of GDM and BMI changes between consecutive pregnancies by examining their association with hospital length of stay (LOS) and related birthing costs.
Study Design and Population
This investigation was conducted at two maternity hospitals in New South Wales, Australia, focusing on women who had two consecutive singleton births between September 2011 and April 2019. A total of 11,157 women met the inclusion criteria. The research utilized hospital records to identify GDM status across pregnancies and to track BMI changes, categorizing weight change into loss (< -1 kg/m²), stable (-1 to <1 kg/m²), small gain (1 to <2 kg/m²), medium gain (2 to <4 kg/m²), and large gain (≥4 kg/m²).
Methodology
The study employed multivariable generalized linear models to analyze the data, assessing the relationships between GDM occurrence (none, only first pregnancy, only second pregnancy, or both pregnancies), interpregnancy BMI changes, and outcomes related to the second birth—specifically hospital LOS and birthing-associated hospital costs. Costs were derived from Diagnosis Related Group (DRG) codes and standardized to 2024 Australian dollars (AUD) for economic relevance.
Results
Among the cohort, 5% of women experienced GDM only during their first pregnancy, 9% only during their second, and 8% during both pregnancies. Women with GDM in both pregnancies had notably longer hospital stays during their second birth, averaging 3.71 days compared to 2.79 days for women without GDM. This translated into hospital costs that were approximately AUD 1,960 higher (AUD 14,680 vs. AUD 12,720).
Statistical adjustments confirmed these trends, showing a 21% increase in LOS and a 9% increase in hospital costs for women with GDM in both pregnancies compared to those with no GDM. Additionally, a large BMI gain (≥4 kg/m²) between pregnancies was linked to a 9% increase in LOS. Importantly, women with both GDM in both pregnancies and large BMI gains faced a 23% longer hospital stay and 9% higher hospital costs for the second birth.
Discussion
These findings highlight the compounded impact of gestational diabetes and considerable BMI gain between pregnancies on healthcare resource utilization during childbirth. Extended hospital stays and increased costs pose significant burdens on healthcare systems and the families involved. From a clinical perspective, the data suggest that closer monitoring and intervention aimed at managing weight and preventing GDM recurrence may reduce hospital resource use.
Preventive strategies such as nutritional counseling, lifestyle modifications including diet and physical activity, and structured postpartum care plans are essential for women planning subsequent pregnancies, particularly after an index birth complicated by GDM. Early intervention could mitigate risks associated with large BMI increases and repeated GDM, improving maternal and neonatal outcomes while reducing economic strain.
Conclusion
Gestational diabetes and interpregnancy BMI gain significantly increase hospital length of stay and birthing-related costs for the second birth. These insights emphasize the importance of integrating comprehensive preventive programs into maternal healthcare policies. By addressing modifiable risk factors such as excessive weight gain and glucose intolerance during pregnancy, healthcare providers can improve outcomes and reduce financial and resource burdens on both families and healthcare systems.
Implications for Public Health and Clinical Practice
Healthcare systems should prioritize interventions targeting women with GDM and those at risk for significant BMI gain between pregnancies. This includes developing supportive public health policies and investing in programs that promote healthy weight management and diabetes prevention during the interpregnancy period. Enhanced patient education and multidisciplinary care coordination are vital to achieving these goals, ultimately fostering healthier pregnancies and reducing economic costs associated with childbirth complications.
References
Mahumud RA, Ross GP, Mackie A, Morton RL, Black KI. The Economic Burden of Gestational Diabetes and Body Mass Index Changes Between Pregnancies: A Retrospective Cohort Study. BJOG : an international journal of obstetrics and gynaecology. 2026-03-10;133(8):1602-1615. PMID: 41808333. Available at: https://pubmed.ncbi.nlm.nih.gov/41808333/