Screening for gestational diabetes mellitus and hyperglycemia in pregnancy with the glucose challenge test administered in early pregnancy.

OBJECTIVE: To determine the cut-off value for the 75-g glucose challenge test administered in early pregnancy to screen for gestational diabetes mellitus and abnormal carbohydrate metabolism in pregnancy. METHODS: A prospective study involving 1500 antenatal patients attending a community hospital. Patients were screened with the 75-g 1-h glucose challenge test in early pregnancy and subsequently tested with the 75-g 2-h glucose tolerance test to diagnose gestational diabetes mellitus. Statistical methods were employed to determine the optimal plasma glucose cut-off value for a positive result in early pregnancy. RESULTS: A glucose challenge test value of 6.0 mmol/L (108 mg/dl) or more was selected as the preferred cut-off level for further testing with a sensitivity of 83.5% (95% confidence interval [CI] 77.0%-88.9%) and specificity of 49.2% (95% CI 46.5%-52.0%). CONCLUSION: An early pregnancy glucose challenge test reading of 6.0 mmol/L (108 mg/dl) or more is effective in screening for gestational diabetes mellitus; a value of 10.0 mmol/L (180 mg/dl) or more is effective for finding pre-pregnancy abnormalities of carbohydrate metabolism. The false-positive glucose challenge test diagnoses gestational hyperglycemia, the treatment of which will improve perinatal outcome. Further testing based on risk factors will exclude a false-negative glucose challenge test. A combination of universal early pregnancy screening and selective risk-factor testing is recommended to detect the full range of abnormalities of carbohydrate metabolism encountered in pregnancy.

Reducing transmission risk through high-level disinfection of transvaginal ultrasound transducer handles.

Intracavity ultrasound transducer handles are not routinely immersed in liquid high-level disinfectants. We show that residual bacteria, including pathogens, persist on more than 80% of handles that are not disinfected, whereas use of an automated device reduces contamination to background levels. Clinical staff should consider the need for handle disinfection.

The importance of infection prevention and control in medical ultrasound.

Infection control and prevention is critical to delivering safe and high-quality care to patients undergoing sonographic procedures. In Australia comprehensive standards for reprocessing of ultrasound probes are based on the AS/NZS, TGA and ASUM recommendations. These standards align with the US Centers for Disease Control and Prevention recommendations. However compliance to these guidelines is not ideal and there exists an unmet need for refinement of the guidelines relating to specific factors in clinical sonography. Significant microbiological evidence exists reflecting the increased risk of infection transmission specifically through inadequately reprocessed ultrasound probes. Studies have reported > 80% of transvaginal ultrasound probe handles are contaminated with disease causing pathogens since handle disinfection is omitted from standard reprocessing protocols. Significantly, it was recently discovered that widely-used high level disinfectants referred to in guidelines are unable to kill HPV while it is becoming increasingly apparent that attention must be paid to the clinical sonography environment as a potential source of nosocomial pathogens. Ultrasound probe reprocessing guidelines and standards are comprehensive however the challenge is in general awareness and effective implementation into practice. As future research in this area is performed, guidelines will need to be amenable to revision to provide patients with the best standard of care.