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Nausea and Vomiting in Pregnancy

by Dr. Cristina M. Persa, MS, ND


Dr. PersaNausea and vomiting of pregnancy commonly occur during the first trimester, between 5 and 18 weeks of pregnancy. In most women, the symptoms typically settle by the second trimester (the fourth month). However, some pregnant women have symptoms throughout their pregnancy and until delivery.

“Morning sickness” is the term often used to describe mild nausea and vomiting. Although morning sickness is more common in the morning, it can happen at any time of the day or night.

Hyperemesis gravidarum” is the term used to describe a more severe condition. Hyperemesis gravidarum may cause you to vomit multiple times throughout the day, resulting in severe dehydration and weight loss (more than 5 percent of pre-pregnancy body weight). It usually requires treatment in the hospital.

The cause of pregnancy-related nausea and vomiting is not known but various theories have been proposed. One theory holds that the rapid increase in hormone levels in early pregnancy and the resultant high levels of progesterone may stimulate the vomit center in the brain. Progesterone also relaxes smooth muscle throughout the body, including arterial muscle and this causes a drop in the blood pressure and the “sickness” feeling.

Low blood sugar (which normally occurs in early pregnancy), slow emptying of the stomach content and psychological factors are among other theories.


A woman is more likely to develop nausea and vomiting in pregnancy if:

-she developed these symptoms in a previous pregnancy

-she has twins or multiple pregnancy

-she has a history of motion sickness

-she has a history of menstrual migraines or has nausea and vomiting while taking oral contraceptive pills

-her mother experienced these symptoms

-has a history of acid reflux or she is obese


What can you do to relieve nausea and vomiting?

There is no standard treatment for nausea and vomiting in pregnancy, as the causes vary from one woman to another. The treatment should aim to help you feel better and allow you to eat and drink enough so that you do not lose weight.

As the first trimester of pregnancy, is the period in which drug therapy is most worrisome, due to the extreme vulnerability of the fetus at that time, it’ll be worth to consider natural  treatment options:

  • Eat small and frequent meals high in carbs (whole grain breads, crackers, pasta, potatoes, brown rice) and proteins and low in fats. Snack on whole grain crackers with nut butters or cheese. Cold meals may be better if nausea is associated with food smells.
  • Drink cold, clear, and carbonated or sour fluids (e.g., ginger ale, lemonade) in small amounts between meals. Peppermint, chamomile or raspberry leaf tea are other good options.
  • Do not sit up or get out of bed too quickly.
  • Smell fresh lemon, mint, or orange or using an oil diffuser with these scents may help control nausea.
  • Vitamin B6 (especially the active metabolic form, pyridoxal-5-phosphate, P5P), 30-75 mg/day, can reduce symptoms of mild to moderate nausea, but does not usually help with the vomiting. Magnesium increases the amount of vitamin B6 that can enter the cells. As a result, these two nutrients are often taken together.
  • Vitamin K3 (menadione) and vitamin C (ascorbic acid) taken at the same time can give remarkable relief of morning sickness. A study published in 1952, reported that 5 mg of vitamin K3 combined with 25 mg of ascorbic acid completely resolved the symptoms within 3 days in 64 (which is 91%) of 70 women. Three more women were relieved of vomiting but remained nauseated. Only three of the 70 women had no results at all. The conclusion was that vitamin K3 and vitamin C must be taken at the same time for the treatment to work. Vitamin K3 is a synthetic form of vitamin K and is available only with a prescription. Capsules containing Vitamin K3 and vitamin C can be prepared by a compounding pharmacy with doctor prescription.
  • Ginger is well known to improve digestion and alleviate nausea. It can be taken in capsules, tea or tinctures, 3-4x/day. The dose of 250 mg 3x/day can alleviate mild to moderate morning sickness. Ginger should be taken only for short period of times and the dose should not exceed 1 gram/day (some experts worry that it could raise the risk of miscarriage, especially in high doses).

Always consult with a healthcare provider before taking any medication or supplements!


Seek help if you have one or more of the following:

  • Signs of dehydration, including feeling “dry” or very thirsty, becoming drowsy or unwell, feeling dizzy with standing, infrequent urination, or your urine changes from a light yellow to a dark yellow or brown color
  • Vomiting repeatedly throughout the day, especially if you see blood in the vomit
  • Abdominal or pelvic pain or cramping
  • If you are unable to keep down any food or drinks for more than 12 hours
  • You lose more than 5 pounds (2.3 kg)



Most women with pregnancy-related nausea and vomiting recover completely without any complications. There is no evidence that nausea and vomiting has a harmful effect on your baby. In fact, women with mild nausea and vomiting may have lower risk of miscarriages and stillbirths.

In women with severe nausea and vomiting (and who lose weight during pregnancy) may, however, have a baby with a lower than expected birthweight.

Women who have hyperemesis gravidarum in one pregnancy have 15-20%   risk of severe nausea and vomiting in future pregnancies. Women who do not have hyperemesis gravidarum in the first pregnancy are unlikely to have it in future pregnancies.



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  2. David Hoffmann. Medical Herbalism The Science and Practice of Herbal Medicine.2003
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