Morning sickness: how long it lasts, symptoms, treatment and when to get help

For most people morning sickness is a feature of the first trimester. NICE CKS says it usually begins between the 4th and 7th weeks of pregnancy, peaks between the 9th and 16th weeks and resolves by 16 to 20 weeks. The NHS gives the same end point: it usually clears up by weeks 16 to 20.

RCOG puts it differently: nausea and vomiting of pregnancy settles by 20 weeks in 9 out of 10 pregnant women, although in some it may last longer. If you still have severe nausea and vomiting after 20 weeks, RCOG advises contacting your midwife or GP, who may offer ultrasound scans to monitor the baby’s growth in later pregnancy.

CKS adds that vomiting that starts after 11 weeks of pregnancy usually suggests another cause unrelated to the pregnancy, and RCOG similarly says other causes should be looked for if sickness only starts after 16 weeks, if you have tummy pain or pain passing urine, or if you have conditions such as a stomach ulcer or gallstones.

For people with hyperemesis gravidarum the picture can last longer. RCOG says that although it can be difficult throughout the pregnancy, the symptoms usually resolve or improve after the baby is born.

The main symptoms are feeling sick (nausea) and being sick (vomiting). Despite the name, the NHS says it can affect you at any time of the day or night, or you may feel sick all day long, and that it is unpleasant and can significantly affect your day-to-day life.

RCOG notes that it can affect your mood, your work, your home and your social life, and that for some women the symptoms are so severe that they become depressed and need extra support such as counselling. If you feel down, speak to your healthcare professional.

Morning sickness becomes a medical problem when you cannot eat and drink normally. RCOG describes signs of dehydration as feeling dry or very thirsty, becoming drowsy or unwell, or your urine changing from light yellow to dark yellow or brown.

Morning sickness, doctors’ term nausea and vomiting of pregnancy, is very common in early pregnancy. RCOG says nausea and vomiting affect most women and usually start in the 4th to 7th week.

It is on a spectrum. Mild to moderate sickness is common and can be treated at home. Hyperemesis gravidarum is the severe end. CKS describes it as nausea and vomiting severe enough to cause an inability to eat and drink normally and to limit daily activities strongly, with signs of dehydration contributing to the diagnosis.

The NHS says to call your midwife, GP or 111 if you are vomiting and you have very dark-coloured urine or have not had a pee in more than 8 hours, you cannot keep food or fluids down for 24 hours, you feel very weak, dizzy or faint when you stand, you have tummy pain, you have a high temperature, you vomit blood, or you have lost weight.

RCOG says that if your symptoms do not settle or stop you doing your daily activities, you should see your GP, who can prescribe anti-sickness medication that is safe in pregnancy. If symptoms are not settling, contact your GP or midwife who will arrange for you to be seen in the assessment unit at your hospital, and you can also get advice from NHS 111.

The NHS notes that urinary tract infections can also cause nausea and vomiting, so a urine test is part of the assessment.

• unable to keep food or fluids down for 24 hours

• very dark urine, or no pee for more than 8 hours

• feeling very weak, dizzy or faint on standing

• tummy pain or a high temperature

• vomiting blood

• weight loss

There is no single treatment that works for everyone, says the NHS, and every pregnancy is different. But there are changes to diet and daily life that may ease the symptoms. The NHS suggests eating something like dry toast or a plain biscuit in the morning, eating small, frequent meals of plain foods that are high in carbohydrate and low in fat (such as bread, rice, crackers and pasta), and eating cold foods rather than hot ones if the smell of hot meals makes you feel sick.

RCOG similarly suggests small amounts of foods that are high in carbohydrate and low in fat, such as potato, rice and pasta, or foods that are easier to tolerate such as plain biscuits or crackers, and avoiding foods or smells that trigger symptoms.

The NHS also advises drinking plenty of fluids such as water, sipping them little and often to help prevent vomiting, and getting plenty of rest because tiredness can make nausea worse.

The NHS says there is some evidence that ginger may help reduce nausea and vomiting, from foods or drinks containing ginger, and that you should check with a pharmacist before taking ginger supplements during pregnancy.

It also says there is some evidence that acupressure, which means pressing on the wrist with a special band or bracelet or with your fingers, may help relieve symptoms. Getting plenty of rest and avoiding foods or smells that make you feel sick are other steps the NHS lists.

If these do not work, or your symptoms are more severe, the NHS says your doctor or midwife might recommend medicine.

For mild sickness, treatment is self-care. If nausea and vomiting is severe and does not improve with lifestyle changes, the NHS says your GP may recommend a short course of an antiemetic (anti-sickness medicine) that is safe to use in pregnancy, often a type of antihistamine, usually as tablets. For severe sickness a doctor may suggest an injection or a suppository.

RCOG lists several medicines. A slow-release combination of doxylamine and pyridoxine (vitamin B6), called Xonvea, is the only licensed treatment for nausea and vomiting in pregnancy in the UK. Cyclizine can be taken by mouth or injection, and prochlorperazine, chlorpromazine and promethazine can be tried if cyclizine has not worked. All of these are considered safe in pregnancy, and occasionally a combination of two or more is needed. Metoclopramide, domperidone and ondansetron are others, usually used if the previous medicines have not worked because of a small risk of side effects.

RCOG adds that if hyperemesis gravidarum is not treated it may cause more harm to the baby than any possible effects of a medicine recommended by your doctor, and that corticosteroids may be considered in severe cases where other measures have failed.

In hospital, RCOG says treatment includes fluids through a drip, anti-sickness medicine, a B vitamin called thiamine, compression stockings and heparin injections because dehydration and being less mobile increase the risk of blood clots. Iron medication can be stopped temporarily because it can make sickness worse.

The NHS says it is thought that hormonal changes in the first 12 weeks of pregnancy are probably one of the causes. RCOG says the cause is thought to be hormones produced in pregnancy in all women, and that research suggests some women get it worse because of genetic differences that lead to higher levels of a hormone called GDF-15, which is produced by the placenta and causes loss of appetite and nausea.

The NHS lists factors that may make it more likely. They include having twins or more, severe sickness and vomiting in a previous pregnancy, a tendency to get motion sickness, a history of migraine headaches, morning sickness running in the family, feeling sick when taking contraceptives containing oestrogen, it being your first pregnancy and a BMI of 30 or more.

The NHS says there is a chance of developing a severe form of pregnancy sickness called hyperemesis gravidarum, which can be serious because you may become dehydrated or not get enough nutrients, and you may need specialist treatment, sometimes in hospital. RCOG says it may affect up to 3 in 100 pregnant women and that 1 in 5 affected women may need admission to hospital.

RCOG says admission may be advised if you are dehydrated, have severe vomiting and cannot keep fluids or oral medication down, have abnormal blood tests, have lost a lot of weight rapidly, or have a medical condition such as a heart or kidney problem, diabetes, epilepsy or HIV and are unable to take medicine by mouth.

CKS adds that women with severe symptoms may lose weight, develop electrolyte imbalance and acute kidney injury, and that hyperemesis gravidarum is linked to preterm delivery, low birthweight and small-for-gestational-age babies, which is why it is monitored and treated. RCOG says women with severe nausea and vomiting may have a baby with a lower than expected birthweight, and you may be offered scans to monitor growth.

On the NHS, your midwife or GP is the first contact. If symptoms do not settle, RCOG says they will arrange for you to be seen in a hospital assessment unit where you may have a check-up, urine and blood tests and an ultrasound scan if you have not had one, and fluids and anti-sickness medicine through a drip if you are unable to drink enough.

Pregnancy Sickness Support, a UK charity, offers information and support for people affected by pregnancy sickness, and the NHS and RCOG both signpost it.