Hyperemesis gravidarum (HG): when it’s more than morning sickness

Lots of people feel sick in early pregnancy. Hyperemesis gravidarum, usually shortened to HG, is different: severe, long-lasting sickness and vomiting that can make it hard to keep food or even water down. It can be treated, and you don’t have to push through it on your own.

What is hyperemesis gravidarum?

HG is severe sickness and vomiting in pregnancy that goes on for a long time. It’s thought to affect around 1 to 3 in every 100 pregnant women. It can lead to dehydration, weight loss and not getting enough nutrition, so it needs medical care. With the right treatment, HG is unlikely to harm your baby.

How it’s different from morning sickness

Ordinary morning sickness often starts at around 4 to 7 weeks and, for most people, eases or stops by 16 to 20 weeks. It can be miserable, but it isn’t harmful to your baby. See morning sickness: what you need to know.

With HG, the sickness is frequent and severe, it may not ease by 16 to 20 weeks, and for some people it lasts until the baby is born. Signs include being sick many times a day, not keeping food or drink down, losing weight and signs of dehydration, like feeling very thirsty or having dark wee.

When to get help

Contact your midwife, GP or NHS 111 if you’re being sick and you:

have very dark wee, or haven’t had a wee for more than 8 hours
can’t keep food or fluids down for 24 hours
feel very weak, dizzy or faint when you stand up
have tummy pain or a high temperature
are bringing up blood
have lost weight

If you’re struggling to keep food down, don’t wait for your next appointment: get in touch with your midwife, GP or hospital as soon as you can. If you haven’t seen a midwife yet, call your GP surgery or NHS 111.

If you have any bleeding, or tummy pain that’s severe, on one side, or not easing after resting for 30 to 60 minutes, or pain in the tip of your shoulder, contact your maternity unit or an early pregnancy unit straight away, or NHS 111 if you can’t reach them. Call 999 if bleeding is heavy (soaking a pad soon after putting it on), or comes with severe tummy or shoulder pain or with feeling sick, faint or dizzy, or if you have sudden, severe tummy pain with feeling faint or dizzy, even without bleeding.

Treatment for HG

Anti-sickness medicines. There are anti-sickness medicines that can be used in pregnancy, including in the first 12 weeks, and your GP can talk you through the options. If one doesn’t work there are others, and some people need a combination.
Fluids through a drip, and sometimes anti-sickness medicine given into a vein or muscle, if you can’t keep fluids or tablets down.
Day care. If you can’t keep tablets or fluids down, you should be offered treatment at a hospital day unit, where you have fluids and medicine and can usually go home the same day.
A hospital stay, if needed.
Thiamine (vitamin B1). If you’re admitted to hospital with vomiting, or you’ve barely been able to eat, you should be given thiamine as tablets or through a drip, because it can run low after weeks of being sick.
Medicine to prevent blood clots. HG slightly raises the chance of a blood clot, although this is rare. If you’re admitted, you may be offered injections to lower the risk.
Steroids, if other treatments haven’t worked.

Check with a GP, midwife or pharmacist before you take any medicine, supplement or herbal remedy for sickness. If pregnancy vitamins with iron seem to make your sickness worse, ask your midwife or GP about switching to one without iron for a while. There’s more in medicines in pregnancy. In England, prescriptions are free while you’re pregnant if you have a maternity exemption certificate.

It’s not your fault

HG is a recognised medical condition. It isn’t caused by anything you did or didn’t do, and it isn’t in your head. Needing treatment doesn’t mean you’re weak or making a fuss. If you don’t feel listened to, it’s OK to say so and keep asking for help.

Looking after your mental health

Being sick for weeks on end is exhausting, and it can affect your mood and how you feel about the pregnancy. Tell your midwife or GP how you’re feeling, not just how sick you are. If you’re worried about your mood or anxiety, they can arrange support. See anxiety, low mood and loneliness in pregnancy.

If you feel you can’t keep yourself safe, call 999 or go to A&E. You can also call NHS 111 and choose the mental health option or Samaritans on 116 123.

Work and sick leave

Acas guidance says sick leave linked to your pregnancy should be kept apart from other sick leave on your record, and shouldn’t count towards absence reviews or trigger points. It’s against the law to discriminate against you because you’re pregnant.

If you’re off sick because of your pregnancy in the 4 weeks before the week your baby is due, your maternity leave starts automatically, along with Statutory Maternity Pay if you qualify. There’s more in pregnancy rights at work.

Support

Pregnancy Sickness Support has a helpline on 0800 055 4361, Monday to Friday, 9am to 4:30pm (check its website for current hours). It can also put you in touch with someone who has had HG themselves.

Questions people ask

Is HG just bad morning sickness?

No. HG is severe, long-lasting sickness and vomiting that can cause dehydration and weight loss, and there’s treatment that can help.

How long does HG last?

It varies. Some symptoms may improve at around 20 weeks, but for some people HG lasts until the baby is born. See when does morning sickness stop?

Will I get HG again?

It’s likely to come back in another pregnancy, but planning ahead helps. Talk to your GP early about starting the medicines that worked last time.