Prescribing in pregnancy: the preventative role of urine in AMR.

Antibiotic resistance is at the forefront of scientific research; new medicines are being sought to replace the antibiotics to which patients are becoming immune due to over-prescribing. The majority of prescribing happens in Primary Care; in antenatal settings, women are routinely checked for anomalies that might affect their health. Prevention is the watchword for safe antenatal screening and urine plays a critical role.

Traditionally, antenatal urine samples are dipped; any positive result indicating excess protein, glucose or bacteria that might point to a urinary tract infection (UTI) or other condition can lead to the immediate prescribing of a broad spectrum antibiotic, which may not target and treat the problem.

The rise of antibiotic immunity has prompted an overdue change to this empirical diagnostic pathway, and guidelines now recommend prescribing targeted to the specific problem, endorsed by recent Public Health England antimicrobial prescribing guidance. Meanwhile, the Royal College of GP flowchart for treating UTI in pregnant women stipulates if pregnant, always send urine culture then follow national treatment guidelines.

In 2015 NICE launched the Start Smart then Focus (3) antimicrobial stewardship toolkit. This says: “do not start antimicrobial therapy until there is clear evidence of infection …..avoid inappropriate use of broad spectrum antibiotics.” That seems clear enough … but contrary to its advice on antimicrobial stewardship (above) Public Health England’s guidelines for treating UTI recommend consideration of immediate antibiotic if a dipstick shows positive leukocyte, yet growing doubts over dipstick methodology imply that it is more likely to lead to inappropriate antibiotic use.

These prescribing improvements, however, are particularly pertinent to pregnant women because taking an antibiotic unnecessarily can affect not just the mother and present a risk of spontaneous abortion, but can impact the unborn child too.

A recent detailed study on antibiotic use in pregnancy suggests that “antibiotics in pregnancy may affect the bacterial ecosystem of the mother as well as that of the foetus, and therefore their use should be carefully considered based on what is known, and what remains unknown, regarding their effects.” This paper also points to childhood conditions such as obesity and asthma resulting from antibiotic use in pregnancy and states that the maternal microbiota during pregnancy actually drives early postnatal innate immune development.

A robust improvement to drive practice change to avoid unnecessary urine-sourced prescribing in pregnancy is to ensure the specimen is midstream and therefore uncontaminated; unreliable and false-positive dipped urines can lead to antibiotic overuse, impacting both mother and child.

All guidelines for urine collection and analysis state that a midstream specimen is needed yet there is no protocol around guaranteeing its collection. Whereas there is a very specific method for collecting blood, urine is left to individual hit-and-miss methods potentially leading to contamination, false-positive urines and unnecessary prescribing, fuelling the AMR crisis from the frontline of women’s health, which is precisely where positive action needs to take place for this and the next generation.

The global AMR crisis points to the need for a radical change in attitudes to urine and its collection because without it, AMR can only get worse; planting the seed to immunity in the unborn can only lead to huge, global diagnostic problems ahead.

Its time to change basic frontline practice around urine collection: to quote Henry Ford, “if you do what you’ve always done, you’ll get what you’ve always gotten”.

Other references

• Medicinesinpregnancy.org
• Behaviour change and antibiotic prescribing in healthcare settings

? Giovanna Forte 2019