Possible Complications

The most common risk with HG is dehydration and not getting enough nutrients, simply because it's so hard to keep food and fluids down. This is exactly why fluids through a drip, and sometimes vitamin supplements, are such a routine part of HG care — not an extreme measure, but a standard response to a standard problem.

We cover this in more detail on the Treatment page, but it's worth repeating briefly here: prolonged vomiting without enough vitamin B1 (thiamine) can, rarely, lead to a serious condition called Wernicke's encephalopathy. This is exactly why thiamine is given proactively in HG care, especially before certain fluids — it's a known risk that your care team is actively managing, not something that happens without warning.

Being dehydrated and less mobile — especially during a hospital stay — can increase the risk of blood clots. This is a well-recognised risk in HG care, which is why your team may offer blood-thinning injections during a hospital admission if your individual risk factors call for it.

This is often the hardest part to think about, so we want to be careful and honest here rather than either alarming you or glossing over it. With proper treatment, most pregnancies affected by HG progress well. Some research has looked at outcomes where HG was severe or went untreated for a long period, and effective treatment is specifically aimed at reducing these risks — which is one of the main reasons early, adequate treatment matters so much.

If you'd like the specific research detail behind this, it's available by expanding "Show the evidence" below — we've kept it there deliberately, since it's the kind of detail that's more useful to read with support nearby than alone at 2am.