Hyperemesis gravidarum is severe vomiting in pregnancy that continues for an extended period of time. Although nausea and vomiting are very common in early pregnancy, and often referred to as morning sickness, it tends to be mild and improves around the start of the second trimester (week 13). In contrast, hyperemesis gravidarum is actually quite rare, only occurring in around 1% of pregnancies, and it can last beyond the 2nd trimester in some cases. If left untreated it can become life-threatening for both the mother and the baby. The good news is that when treated effectively, there should be no long-term complications for mother or baby.
With hyperemesis gravidarum, the extended period of nausea and vomiting causes difficulty in keeping food or drink down resulting in weight loss, dehydration, and changes in levels of salts in the body (known as electrolytes). In the majority of cases, hyperemesis gravidarum needs treatment in the hospital with rehydration (usually through a drip in the arm), along with monitoring, correction of salt imbalances, and sometimes the use of anti-sickness medication. Symptoms of dehydration might be felt, such as feeling thirsty, dry lips and skin, lightheadedness and dark-coloured urine.
It is unknown exactly why a small number of women in pregnancy develop hyperemesis gravidarum, but it is thought to be to do with certain hormone levels, combined with some genetic factors. You are more at risk of developing hyperemesis gravidarum if you or a family member have suffered from hyperemesis gravidarum before.
See your doctor or midwife as soon as you can if you have severe vomiting or cannot keep any water or food down. If you start to feel dizzy or faint or have palpitations (when you can feel your heart beating hard or fast in your chest), call NHS 111 or book an urgent on-the-day doctor's appointment. In the event of someone collapsing call 999 or your local emergency services number immediately.
The doctor will ask you about your symptoms such as when they started, along with details about your pregnancy, including your due date and any complications. It's helpful to take your pre-natal notes with you to any appointment. They will also ask about your past medical history, any relevant family history, and about any medications you are taking. Your baseline health measurements will be taken such as checking your heart rate, blood pressure and your weight. It is likely you will also have some blood tests done and may be asked to do a urine sample. Often people suffering from hyperemesis gravidarum will need treatment in hospital - your doctor or midwife will refer you to hospital when necessary.