Your thoughts: Embrace the evidence

By Caitlin Dean on 25 May 2018 Midwives Magazine Hyperemesis gravidarum

Caitlin Dean is frustrated that practitioners continue to ignore the evidence gaps in hyperemesis gravidarum care.

Hyperemesis gravidarum (HG) is a dreadful condition that can last for months, creating relationship problems, finance difficulties and affect women’s sanity. It’s not hard to imagine that constant, profound nausea every waking moment for more than just a few days would start to make you miserable. Add to that the vomiting, which can be violently suffocating and humiliating, and you can start to understand the long-term trauma HG can leave in its wake. Yet despite the debilitating effects, accessing compassionate, supportive and above all evidence-based care can be surprisingly difficult.

There are a number of evidence practice gaps in HG care but, for me, the most frustrating, harmful and tenacious gap is in the continued reliance on the marks of ketonuria for assessment, diagnosis and treatment decision-making. Ketones are not an indicator of dehydration – they are a by-product of the body metabolising stored fat when it is low on glucose to burn. Some people will start producing them if they don’t snack before lunch, whereas others might not have eaten for days but managed to drink 50ml of sugary squash and have no ketones in their urine when it’s dipped. So ketones are not particularly reliable as an indicator for malnutrition.

Most importantly, ketones have been shown by systematic review evidence to not correlate in any way with the severity of HG (Niemeijer et al, 2014). But what’s the harm in checking for ketones? My view is that there is a problem with this approach as it is common for seriously dehydrated women, who are suffering immensely, to be turned away without IV rehydration because they don’t have ketones, or worse, ketones in their urine.

Some healthcare professionals have become so reliant on ketones as the sole diagnostic criteria that they disregard their clinical experience and knowledge of the signs and symptoms of dehydration. It’s not uncommon for me to speak to women so dehydrated they can’t produce a urine sample, who have been turned away from a hospital because staff couldn’t check their ketone level. Not only is that a dangerous situation for mother and baby, but the psychological effect of such a dismissal of a serious illness can have a profoundly negative impact.

In my opinion, there is a simple solution that could universally improve access to care and treatment for women with HG, and that is to embrace the evidence and disregard the ketones. Instead, ask women about their symptoms – then believe what they say. If a woman has got any signs of dehydration, give her the IV fluids because it will make her feel much better, even if only until the next time.

Caitlin Dean is chair of Pregnancy Sickness Support and raises HG awareness at