Hyperemesis Gravidarum: Hidden No More?
- Hamilton Morrin
- 3 hours ago
- 5 min read
What I learnt from my wife’s experience, and why we do ourselves a disservice when we reinforce a mind-body divide
Most of us will know that nausea and vomiting are common in pregnancy, affecting up to 70% of pregnant women. Less well known is hyperemesis gravidarum, or HG, in which nausea and vomiting reach a severity such that women struggle to eat or drink, often losing weight or becoming dehydrated, sometimes to the extent that they require intravenous fluids. As a neuropsychiatric doctor and researcher at King’s College London, I have a particular interest in the overlap of physical and mental health. Whilst I had a general awareness of HG from my medical training, it’s safe to say that I had never truly grasped just how debilitating and difficult to treat this disorder could be.
Without going into detail, in late 2024 my wife Yasmeen developed HG while pregnant with our first child. She spent the next seven-to-eight months struggling with almost relentless nausea and retching, regularly calling in sick to work, and trialling first, second, and third-line treatments with little effect. At the time, I was reminded of a lecture in medical school during which an ENT professor emphatically informed us that persistent nausea can be just as debilitating as chronic pain.
Last year, thanks to my good colleague and friend Dr Tom Pollak, I was given the opportunity to access TriNetX, an international database of anonymised health records. Perhaps in an act of sublimation, I decided to focus on the issue at the forefront of my mind, and attempt to answer the question, what happens to the mental health of women with HG?
What Causes HG and How Might It Affect Mental Health?
If you speak with anyone who has been affected, or cared for someone with HG, then you’ll know that it would be an understatement to describe the illness as “morning sickness”. HG can often leave women unable to care for themselves, work, or take part in family life, and this can sometimes persist beyond the first trimester through to delivery. Despite its severity, HG has long been underrecognised and inadequately treated, with patients reporting disbelief and difficulty accessing care.
For much of the twentieth century, the underlying cause of HG remained the subject of inquiry, with proposed mechanisms ranging from hormonal sensitivity and gastrointestinal motility to metabolic and psychological drivers. Today we have compelling evidence for a causal pathway. Research led by Dr Marlena Fejzo and colleagues has shown that GDF15, a hormone produced largely by the fetus and placenta, and the mother's sensitivity to it, both contribute substantially to HG.
As a clinician working in neuropsychiatry, it is easy to appreciate the enormity of identifying a putative biological marker of disease, not least as it may open the door to novel methods of diagnosis, monitoring, and targeted treatments. That it should require the discovery of a biomarker for an individual’s illness and suffering to be seen as valid by wider society or be considered treatable is perhaps a separate issue, one which I am certain many colleagues in mental health services can empathise with.
There have now been several articles in the general media regarding tragic outcomes in women with HG linked with mental health. Similarly, important work by colleague Melanie Nana has served to shine a light on the psychological impacts of HG, finding that a quarter of women with HG had thoughts about suicide. Other studies have found increased rates of depression, anxiety and PTSD in women with HG, though the largest studies to date numbered in the hundreds to thousands of participants.
What Did Our Study Find?
In our study, we identified 476,857 pregnant women with HG across 18 countries. We matched each of them with a pregnant woman without HG who was similar on factors including age and previous physical and mental health diagnoses. We then examined new diagnoses recorded during pregnancy and roughly three months following delivery.
We found that women with HG had an increased risk of various mental health conditions. A new diagnosis of depression was recorded in almost 8% of women with HG, compared with about 4% of matched pregnant women. Postpartum depression was nearly three times as common, and anxiety disorders were almost twice as common. We also found higher risks of PTSD, eating disorders, suicidal thoughts and, although still rare in absolute terms, puerperal psychosis.
One finding initially came as a surprise. Women whose HG was coded as involving metabolic disturbance, such as dehydration or electrolyte imbalance, had lower recorded rates of depression than women whose HG was labelled "mild". Initially, not knowing what to make of this, I asked Yasmeen for her thoughts, to which she suggested that perhaps women with metabolic disturbance were more likely to be admitted to hospital, and that this might in turn impact their experience of care and validation. We were able to check and confirm the former suggestion, that women with metabolic disturbance were indeed more likely to be admitted to hospital, and we saw that the latter postulation was in line with previous qualitative findings regarding the importance of recognition and validation from health-care professionals.
What can we take from this? Perhaps that absence of metabolic disturbance is not absence of need, and that everyone with HG deserves to have both their physical and mental health taken seriously.
Moving Beyond Mind Versus Body
Earlier this year, I was invited to present our findings at the International Conference for Hyperemesis Gravidarum in Bergen where I also led a discussion on priorities for mental health research. Around the table were healthcare professionals, researchers, lived experience representatives, and many who occupied more than one of those roles.
A recurring theme in the discussion was that of difficulty in accessing mental health care. Whilst many individuals found support groups helpful, a number shared how they had been told, often by healthcare professionals, that as their distress and low mood were linked to a physical condition, there was little that could be done to support them psychologically.
Sadly, this picture is perhaps not uncommon. Despite guidance from the Royal College of Obstetricians that all women with HG should undergo routine assessment of their mental health, we know that screening is happening in less than half of UK maternity services. Arguably, this speaks to a need for services to move beyond the historical Cartesian division of mind and body, and to implement integrated care which recognises the psychosocial burden of HG.
Reasons for Hope
Bergen was also full of reasons for optimism. We heard about research into metformin (a medication used to treat type 2 diabetes and gestational diabetes) before pregnancy as a possible way of reducing recurrence of HG, and novel treatments designed to block GFRAL, the brain receptor through which GDF15 signals and causes nausea and vomiting.
I was equally inspired by talks from clinicians, including Dr Andrew Housholder, who presented emerging evidence that mirtazapine and olanzapine may help some women with treatment-resistant HG. Whilst these are off-label approaches that require further study, they serve as an exemplar of what might be possible when we overcome traditional boundaries between psychiatric and medical.
Last year, Yasmeen and I saw The Hidden Mothers, Clare Hughes's participatory exhibition about HG, at Science Gallery London. Drawing on the Victorian practice of concealing mothers behind fabric while their children were photographed, the exhibition gave poignant visual form to how women with HG, and their struggles, often go unseen. Whilst public conversations and research developments are helping to bring HG into the light, only time will tell whether this will translate into the provision of integrated services and pathways for holistic care.
Afternote:
If anyone reading this article is, or cares for somebody affected by HG, there are charities such as Pregnancy Sickness Support and the HER Foundation which have dedicated resources and support groups.
