Nausea is very common during pregnancy especially in first trimester. Some women also experience vomiting. Symptoms may be worse in the morning which gave rise to the term "morning sickness". More women have nausea and vomiting throughout the day and worse in the evenings. Some women have no nausea or vomiting.
Nausea usually starts after 5 weeks of pregnancy and peaks around 9 weeks gestation. For most women the nausea resolves around 12 weeks and they are eating normally by 14 weeks gestation. For others the nausea and vomiting may last longer during the pregnancy. For some women the nausea will persist throughout the whole pregnancy and they feel better on the second day after having their baby.
Mild nausea may return after 34 weeks gestation. Nausea and vomiting are common during labour. The bowel becomes inactive and hormones and mechanical pressure increase the chance of reflux and vomiting.
Management of Nausea and Vomiting in Pregnancy
With nausea and vomiting during pregnancy, it is important to avoid dehydration. This may require taking small, frequent sips of fluid. A solution of Gastrolyte or Hydralyte which contains electrolytes that mimic blood serum may provide better fluid replacement than plain water. These solutions are available as small ice blocks that can melt on the tongue and may be easier to swallow than fluid. Another option for an electrolyte solution is a mixture of 1-part soft drink to 3-parts water.
It is not necessary to force yourself to eat normal meals in early pregnancy. Small healthy snacks frequently may help with nausea. Women often crave carbohydrates and bland food such as crackers and toast will suffice. Eating can be a challenge as not eating or eating too much may make nausea and vomiting worse.
Some women find that ginger in various forms or fruit acid or chewing gum may be helpful. Vitamin B6 or Pyridoxine can help with symptoms of nausea. There are tablets that combine Pyridoxine and ginger which can be obtained without a script.
Common oral medications to help with nausea and vomiting are Metoclopramide (Maxolon) tablets and Ondansetron (Zofran) wafers or tablets. Maxolon can have the side-effect of drowsiness so it is best to avoid before driving. Ondansetron is often more effective but is more expensive. Ondansetron can be associated with worsening of constipation. Other medications available include Antihistamines such as Doxylamine Succinate (Restavit) and Diphenhydramine (Benadryl). Antihistamines are best taken before bed as they cause significant drowsiness.
If nausea and vomiting results in dehydration, then attending the Pregnancy Assessment Centre for intravenous fluids and intravenous or intramuscular anti-emetics (metoclopramide or ondansetron) may be necessary. Longer admissions to hospital may be required if there is significant weight loss (more than 10 kg) or persistent vomiting. Sometimes steroids, such as Prednisone, can be used to reduce nausea and vomiting and improve oral intake.
Reflux symptoms (heartburn, indigestion, nausea and vomiting) are common in pregnancy due to increased acid being squeezed from the stomach and irritating the oesophagus and throat. During pregnancy the muscular sphincter at the top of the stomach is more relaxed and as the pregnancy increases in size, the increased pressure on abdominal contents causes more reflux of stomach acid.
Antacids (such as Mylanta, Gaviscon, Tums, Quik Eze) may reduce symptoms in the short term. If antacids are needed more than twice a day, then medications that reduce stomach acid such as Ranitidine (Zantac) can be more useful in controlling symptoms. Smaller meals, drinking less fluid with meals and not lying down soon after eating may reduce reflux symptoms.