Nausea & Vomiting in Pregnancy

mitra latifiyan - midwife vancouverArticle by Mitra Latifiyan, RM

Better known as morning sickness, this condition affects an estimated 80% of pregnant women during weeks 5-18. A generally mild condition that may be managed with simple measures, the severity of these symptoms can vary.

A small percentage of pregnant women experience more severe onset of nausea and vomiting, with the most severe form being a condition called hyperemesis gravidarum. Although the definition of this condition has not been standardized, accepted clinical features include persistent vomiting, dehydration, ketosis, electrolyte disturbances, and weight loss of more than 5% of body weight.

Causes of Morning Sickness

The causes of nausea and vomiting during pregnancy remains unknown, but a number of possible causes have been investigated. Gastrointestinal tract dysfunction, elevated levels of some hormones- such as human chorionic gonadotropin (hCG) & estrogen- and chronic infection with Helicobacter pylori may play a role.

Mitra Latifiyan, Registered Midwife
Electra Health Floor – 970 Burrard Street, Vancouver
Open 7 days a week from 8 am to 8 pm
604-685-4325 (HEAL)

Treating Nausea and Vomiting in Pregnancy

There are both non-pharmacalogical and pharmalogical approaches to treat morning sickness.

Non-pharmacological interventions:morning_sickness

  • Avoid triggers such as
    • Stuffy rooms
    • Odours (eg. perfume, chemicals, coffee, food, smoke)
    • Heat and humidity
    • Noise
    • Visual or physical motion (eg. flickering lights, driving)
    • Excessive exercise
    • Being tired
    • Consuming large amounts of high-sugar foods/snacks
    • Consuming spicy foods and high-fat foods
    • Stress
  • Brushing teeth after eating
  • Avoid lying down immediately after eating
  • Avoid quickly changing positions
  • Take prenatal vitamins before bed with a snack
  • Dietary changes:

Avoiding food or not eating may actually make nausea worse.

Clinicians commonly recommend eating frequent, small, carbohydrate meals, such as crackers or dry toast. Dietary changes that help some women include eliminating coffee and spicy, odorous, high fat, acidic, and very sweet foods, and instead substituting snacks/meals that are high in protein, salty, low fat, bland, and/or dry (such as nuts, pretzels, crackers, cereal, toast).

Fluids may be better tolerated if cold, clear, and carbonated and/or sour (such as ginger ale, lemonade, popsicles).

Drinking peppermint tea or sucking peppermint candies can reduce nausea.

Try eating ginger containing foods (for example: ginger lollipops, ginger tea) or ginger supplements.

The smell of fresh lemon, mint, or orange, or using an oil diffuser with these scents, may also help to alleviate the symptoms.

  • Acupuncture and Acupressure
  • Hypnosis

Pharmacologic treatment:

  • Intravenous Fluids

Pregnant women who are unable to keep down liquids and are dehydrated, or have abnormal electrolyte levels, may require intravenous fluids.

  • Vitamins and Minerals

 If the patient is experiencing persistent vomiting, it is important to replenish low levels of vitamins, electrolytes, and minerals.

  • Pyridoxine (vitamin B6)  

Pyridoxine has a good safety profile with minimal side effects; improves mild to moderate nausea, but does not significantly reduce vomiting.

  • Antacids

Minor symptoms can be treated with antacids containing calcium carbonate.

  • Doxylamine succinate and pyridoxine 

Doxylamine is an antihistamine, and pyriodoxine is Vitamin B6. The combination of these two has been studied and is recognised by Health Canada as safe and effective for pregnant women, with no harmful effects experienced by the infants. In Canada, this is available as a medication called Diclectin®

**There are other medications that may be suitable. Speak to your midwife about these options.

When to seek help:

  • If you are urinating infrequently, have dark coloured urine, and or dizziness with standing- these are symptoms of dehydration.
  • If you are vomiting repeatedly throughout the day.
  • If you see blood in your vomit.
  • If you are experiencing abdominal or pelvic pain/cramping.
  • If you are unable to keep down any food or drinks for more than 12 hours.
  • If you lose more than 5 pounds (2.3 kg).

Alternative Causes of Nausea and Vomiting

Not all nausea and vomiting during pregnancy is necessarily related to morning sickness. It is important to rule out other causes if the case appears to be more severe, such as food poisoning, allergies, stomach bugs or parasites, or even other digestive or health issues.


1.Matthews A, Haas DM, O’Mathúna DP, Dowswell T. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev 2015; :CD007575.

2. Dodds L, Fell DB, Joseph KS, et al. Outcomes of pregnancies complicated by hyperemesis gravidarum. Obstet Gynecol 2006; 107:285.

3. Magee LA, Mazzotta P, Koren G. Evidence-based view of safety and effectiveness of pharmacologic therapy for nausea and vomiting of pregnancy (NVP). Am J Obstet Gynecol 2002; 186:S256.

4. Goodwin TM. Nausea and vomiting of pregnancy: an obstetric syndrome. Am J Obstet Gynecol 2002; 186:S184.

5. Holmgren C, Aagaard-Tillery KM, Silver RM, et al. Hyperemesis in pregnancy: an evaluation of treatment strategies with maternal and neonatal outcomes. Am J Obstet Gynecol 2008; 198:56.e1.

6. Niebyl JR. Clinical practice. Nausea and vomiting in pregnancy [published correction appears in N Engl J Med. 2010;363(21):2078]. N Engl J Med. 2010;363(16):1544–1550.

7. Lee NM, Saha S. Nausea and vomiting of pregnancy. Gastroenterol Clin North Am. 2011;40(2):309–334vii.

8. QUINLAN J, HILL DH. Florida Nausea and Vomiting of Pregnancy Am Fam Physician. 2003 Jul 1;68(1):121-128.

9. Associans of Obstetricians in Canada Website: https://sogc.org/

10. Patient website: patient.info/health/morning-sickness-in-pregnancy

11. Nuangchamnong N, Niebyl J. Doxylamine succinate–pyridoxine hydrochloride (Diclegis) for the management of nausea and vomiting in pregnancy: an overview. Int J Womens Health. 2014; 6: 401–409.

12. Mother Risk. http://www.motherisk.org/women/updatesDetail.jsp?content_id=875

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Midwifery – Vancouver

Mitra Latifiyan, Registered Midwife
Electra Health Floor – 970 Burrard Street, Vancouver
Open 7 days a week from 8 am to 8 pm
604-685-4325 (HEAL)