How Common Is Hyperemesis Gravidarum? UK Statistics Explained
If you're looking this up, you're probably trying to make sense of what's happening to you, or to someone you love. Here's what we actually know, in plain terms — with the full evidence one click away if you want it.
Written by The HG Collective · Reviewed by clinical team · Last reviewed: January 2025
You are not rare, and you are not alone
Somewhere between 1 and 3 in every 100 pregnancies involve HG. That's the range doctors and the NHS use, and it means that in any large maternity unit, HG is something staff see regularly — not a strange or unheard-of condition.
You'll sometimes see the figure "30,000 women a year" in the UK. That number is a reasonable estimate, but it's worth knowing it's built from the percentages above, not a figure someone counted directly. Depending on which end of the range is used, the real number is probably somewhere between 10,000 and 29,000 a year. We'd rather give you the honest range than a tidy number that sounds more precise than it is.
How many people end up in hospital with it?
Not everyone with HG needs hospital care, but a lot of people do. The best UK research — looking at over 8 million pregnancies in England — found that about 1 in every 65 to 70 pregnancies involved at least one hospital admission for HG.
Of the people admitted:
- Most (around 7 in 10) only needed one admission
- But almost 3 in 10 were readmitted at least once — so if you've been back in hospital more than once, that is a common experience, not a sign that something unusual is happening
Early support matters. Other research looking at GP and hospital records together found that hospital admission figures alone understate how many people are actually affected — a lot of HG is managed (or under-managed) outside hospital, in primary care.
What HG can actually do to your body
This isn't "bad morning sickness." Left unsupported, HG can lead to:
- Not being able to keep food or fluids down at all
- Dehydration and rapid weight loss
- Imbalances in your body's salts and nutrients
- The need for a hospital admission for fluids through a drip
Doctors are advised to consider hospital assessment if you're dehydrated, can't keep down fluids or medication, are losing weight quickly, or your blood tests come back abnormal. If any of that is happening to you, it's a legitimate reason to be seen — not something to push through alone.
The part people talk about least — the mental health toll
This is where the evidence is strongest, and it matters more than the physical numbers alone.
In one UK study of people admitted to hospital with HG:
- Nearly half had signs of probable depression during pregnancy — compared to just 6 in 100 of people without HG
- Almost 3 in 10 had signs of probable depression after birth
In a separate, larger UK survey of over 5,000 people with HG:
- About 1 in 4 said they'd had suicidal thoughts occasionally because of how unwell they felt
- A further 1 in 15 said they'd had these thoughts regularly
Put together, roughly 1 in 3 people with HG in that survey experienced some suicidal thoughts. If that's you, or has been you — you are not alone, this is a recognised part of how severe HG can feel, and it's a reason to reach out for support, not a reason to feel ashamed.
A gap in early identification
Even though HG is common and can be identified early, most maternity units don't routinely screen for it at your first booking appointment. National guidance says this early appointment (by around 10 weeks) should be used to flag risks like this — but in practice, most units don't ask.
Want more information?
Understanding HG is the first step. Visit our Understanding HG page for comprehensive information, or check out our Get Support resources.