Environmental sustainability has emerged as an important priority in modern healthcare. In Australia, healthcare accounts for around 7% of total CO₂e emissions.¹ Working in obstetrics and gynaecology offers a unique opportunity for sustainable innovation where we care for women, pregnant patients, and newborns, who are among the most vulnerable to the health impacts of climate change.²

Screening for gestational diabetes mellitus (GDM) highlights both the challenges and opportunities for sustainable practice. The Pregnancy Oral Glucose Tolerance Test (POGTT), while seemingly routine, is in fact a resource-intensive pathway involving patient travel, laboratory consumables, multiple blood draws, and energy-heavy processing.

The Carbon Cost of a “Simple” Test

The POGTT involves many steps that cumulatively contribute to a significant environmental impact:

• Single-use consumables: Each test typically requires plastic specimen tubes, vacutainers, glucose drink containers, gloves, wipes, and syringes. These are all single-use plastics destined for incineration or landfill.
• Pathology processing: Each blood draw (usually fasting, 1-hour, and 2-hour samples) requires energy-intensive processing in laboratories.
• Patient transport: Patients are often required to travel to hospitals or collection centres while fasting, frequently relying on a support person for transport. This not only contributes to fuel use and associated emissions but also incurs indirect costs through workforce absenteeism. These burdens are particularly amplified in rural and remote areas.
• Packaging and supply chains: The production and transportation of glucose solutions and consumables further increase the carbon footprint.

The carbon footprint of pathology tests commonly used in the hospital setting (full blood examination, coagulation profile, U&E, CRP, ABG) range between 0.5 and 116g CO₂e, equating to driving between 3m and 800m in a car.³ To our knowledge, no peer-reviewed studies have specifically measured the CO₂e emissions of the HbA1c test or the POGTT. However, logical inference suggests that the POGTT would generate substantially higher environmental impact due to requiring three blood collections compared to the HbA1c’s single draw, plus additional glucose solution production and packaging requirements. When multiplied by the hundreds of thousands of POGTTs performed annually in Australia alone, the environmental impact becomes substantial.

Waste and Resource Intensity

Waste produced from a POGTT is non-trivial:

• Plastic waste: Each test can generate greater than 10-15 pieces of single-use plastic, most of which are not recyclable due to contamination with biological material.⁴
• Sharps waste: Needles and lancets must be disposed of as clinical waste, requiring high-energy incineration.
• Chemical reagents: Laboratory reagents have environmental costs both in their manufacture and disposal.

These inputs are high compared to other tests such as the HbA1c, which requires a single blood sample. The use of early HbA1c testing in women at risk of hyperglycaemia may in turn reduce the number of POGTTs performed. This is where the latest Australasian Diabetes in Pregnancy Society (ADIPS) 2025 Consensus Guidelines⁵ offer a pathway to reduce this carbon footprint while maintaining, and hopefully improving, clinical outcomes.

Moreover, the adoption of higher diagnostic thresholds for GDM recommended within these guidelines is expected to yield further environmental benefits. By reducing the number of women classified as having GDM, downstream demand for resource-intensive care pathways – including additional clinic appointments, growth ultrasounds, dietary and endocrinology consultations, increased intrapartum surveillance, and higher rates of induction of labour may also be reduced.⁶ Each avoided diagnosis translates into fewer episodes of patient travel, less utilisation of single-use consumables, and diminished reliance on energy-intensive imaging and monitoring infrastructure. This refinement therefore aligns not only with evidence-based practice to minimise over-diagnosis and intervention, but also with healthcare sustainability goals.

The 2025 ADIPS guidelines represent more than updated clinical recommendations. They highlight how evidence-based medicine can simultaneously improve patient care and promote environmental stewardship. Through targeted testing, refined diagnostic thresholds, and reducing low-yield intervention, clinicians can deliver excellent outcomes while lowering carbon emissions and resource use. As the climate crisis intensifies, healthcare systems must show leadership in sustainability. Building on this, the RANZCOG Environmental and Sustainability Committee (EnSC) is committed to advancing education and advocacy in sustainable healthcare. This includes developing tailored eLearning modules and resources for the Australian and Aotearoa New Zealand context, creating a specialty-specific sustainability audit tool, and embedding sustainability principles into everyday clinical practice. Importantly, they also advocate for audits and research into best practice, high-value, and cost-effective healthcare, to routinely incorporate a sustainability component, ensuring that environmental impact is considered alongside clinical and economic outcomes.