Morning sickness describes nausea and vomiting that many experiences during pregnancy. The term ‘morning sickness’ is misleading because symptoms of nausea and vomiting can occur at any time of day. While there is no cure for morning sickness, there are recommendations that may improve symptoms or at least make them tolerable.
Morning sickness affects up to 80% of pregnancies.
Symptoms vary from mild to severe.
Studies suggest that hormonal shifts play a role in morning sickness.
There are lifestyle changes you can make which may alleviate some symptoms.
What causes morning sickness?
Morning sickness or Nausea and Vomiting of Pregnancy (NVP) has mild to severe symptoms and occurs in 70-80% of pregnancies. Generally, NVP resolves between 14 and 16 weeks of pregnancy. In 10-20% of pregnancies, nausea and vomiting can continue until delivery.
The cause of NVP is unknown but many studies have suggested contributing factors. One of the most convincing factors involves hormones. Following implantation - when a fertilized egg attaches to the uterine lining - there is a major hormonal shift of estrogen, progesterone, and human chorionic gonadotropin (hCG). The hormone hCG promotes the growth of the uterine lining for the growing embryo and signals the body to stop menstruation.
Studies suggest that this hormonal shift, especially the production of hCG could be responsible for nausea and vomiting. Every pregnancy involves the production of hCG but evidence has shown that higher levels of hCG are linked to greater severity of NVP symptoms. Conditions in which higher levels of hCG are present include:
- Multiple gestation pregnancy- such as twins and triplets.
- Female fetuses.
- Down Syndrome and other abnormal chromosome conditions.
- Molar pregnancy – a rare complication of pregnancy characterized by abnormal growth of cells intended to become the placenta.
Research has also suggested that the placenta may play a role in NVP.
Morning sickness can decrease the quality of life and lead to physical and emotional strains that can continue beyond delivery. Several consequences have been observed, including negatively impacted personal relationships, stressed professional relationships due to missed work, depression, and longer postpartum recovery times.
How to help morning sickness
No treatment has been identified that eliminates NVP, but there are many tips available that can improve or limit morning sickness.
1. Lifestyle changes
These changes can be implemented immediately at home. Find what works for you.
- Drink plenty of water throughout the day, at least 2 liters.
- Aim for small, frequent meals every 1-2 hours throughout the day.
- High-fat, high-protein snacks such as nuts.
- Simple carbohydrate snacks upon waking such as crackers or rice cakes.
- Reserve drink consumption before or after a meal, not during.
- Avoid strong-smelling or tasting foods.
- Adequate sleep.
2. Non-pharmacologic therapies
Non-pharmacologic therapies still require collaboration with your Provider.
Peppermint candies or tea after meals can have a soothing effect on the stomach.
- Ginger candy chews, ginger tea, or taken raw can have a soothing effect on the stomach.
3. Pharmacologic therapies
These solutions would be prescribed by your Provider and are to be used together with lifestyle changes and non-pharmacologic therapies.
- Antihistamines (such as Benadryl).
- Vitamin B6 (Pyridoxine).
- Doxylamine (such as Unisom).
- Metoclopramide (such as Reglan).
- Doxylamine- Pyridoxine (such as Diclegis).
When morning sickness becomes Hyperemesis Gravidarum
Hyperemesis Gravidarum (HG) is severe morning sickness. HG generally lasts from 6 - 16 weeks pregnant. However, many people struggle with HG before 6 weeks and until delivery or beyond. Nausea and vomiting in HG are severe enough to cause:
- Weight loss of more than 5% of the pre-pregnancy weight.
- Ketosis - when your body burns fat for energy instead of sugar.
- Activity limitation.
- Electrolyte imbalances.
- Vitamin deficiencies.
- Acute Kidney Injury (AKI).
- Cardiac arrhythmias.
Pregnancies that are complicated by HG will often require additional treatments than those listed above. Treatments may include other anti-nausea and antiemetic (anti-vomiting) medications, intravenous fluids, intravenous medications, and nutritional support. Speak with your provider if you are experiencing severe vomiting without relief from other measures and/or symptoms that are limiting food and water intake.
Impact of morning sickness on the infant
Despite the serious impact that NVP can have on the parent's suffering, studies have shown that the growing fetus remains largely unaffected during mild to moderate symptoms. NVP is associated with positive outcomes including:
- Lower risk of low birth weight baby.
- Lower risk of preterm delivery.
- Lower likelihood of miscarriage.
Conversely, studies have demonstrated that in severe morning sickness or Hyperemesis Gravidarum there is an increased risk of:
- Intrauterine Growth Restriction (IUGR) - poor growth of the baby while in the uterus.
- low birth weight - likely due to maternal malnutrition.
- birth before 37 weeks.
- low APGAR score – a well-being score assigned to the baby at birth.
NVP is often considered a ‘rite of passage’ during pregnancy. The symptoms are highly variable, and every pregnancy is different. If you are suffering from symptoms, it is important to try some lifestyle changes. Do not hesitate to speak with your provider if you feel you need additional support.
- National Library of Medicine. Physiology, Pregnancy.
- The American Journal of Gastroenterology. Hyperemesis Gravidarum and Nutritional Support.
- Mayo Clinic. Morning sickness - Symptoms and causes.
- National Library of Medicine. Nausea and Vomiting of Pregnancy-What’s New?
- National Library of Medicine. Optimal management of nausea and vomiting of pregnancy.
Show all references
- National Library of Medicine. Nausea and Vomiting of Pregnancy.