Nausea and vomiting in pregnancy

Question 1

What is the typical onset and duration of Nausea and Vomiting in Pregnancy (NVP)?

Answer 1

NVP usually starts around 5 weeks of pregnancy and is at its worst at about 9 weeks. It typically disappears by about 16 to 18 weeks.

Question 2

What percentage of pregnancies are affected by NVP in the first trimester?

Answer 2

NVP affects up to 90% of pregnancies in the first trimester.

Question 3

What is nausea

Answer 3

An unpleasant, painless subjective feeling that one will imminently vomit.

Question 4

What is vomiting

Answer 4

Forceful expulsion of gastric contents.

Question 5

What is retching

Answer 5

Strong involuntary reverse movements of the stomach and esophagus without vomiting.

Question 6

What is hyperemesis gravidarum

Answer 6

A severe persistent form of pregnancy-related vomiting causing weight loss and dehydration, requiring hospitalization and further investigations.

Question 7

When is nausea and vomiting in pregnancy no longer called that

Answer 7

When it progresses into a severe form of disease which causes physiological irregularities

Question 8

Describe the pathogenesis of NVP. (8)

Answer 8

• it involves biological, endocrine, physiological, and psycho-social factors.
• The major mechanism is related to the vomiting hormone, Growth Differentiation Factor-15 (GDF15), which causes loss of appetite, nausea, vomiting, and weight loss. - - HCG and GDF15 are produced by the placenta, peaking in the first half of pregnancy.
• Variation in GDF15 gene is associated with HG
• Rise in HCG and progesterone in the first trimester causes relaxation of the esophageal sphincters cause expulsion of gastric contents
• Initial Trigger: Pregnancy induces elevated levels of HCG, oestrogen, progesterone, and GDF15, largely from the placenta.
• GIT Impact: Hormonal changes cause delayed gastric emptying and gastroesophageal reflux.
• Hormonal and gastric changes, along with elevated GDF15 levels, activate the CTZ and vomiting centre in the brain.

Question 9

What are some exacerbating factors of NVP (4)

Answer 9

• Genetic predisposition
• psychological stress
• nutritional deficiencies
• H. pylori infection

Question 10

List the risk factors for NVP. (10)

Answer 10

• Previous history of nausea and vomiting
• Family history
• BMI >30 before pregnancy
• History of migraines
• History of motion sickness
• Multiple gestations
• Trophoblastic disease
• Nulliparity
• Maternal age less than 20
• History of other GI problems like GERD

Question 11

What are the differential diagnoses for NVP? (5)

Answer 11

1. GUT: Urinary tract infections
2. GIT: Esophagitis, GERD, IBS, Paralytic Ileus/Bowel Obstruction
3. Systemic: Malaria
4. Endocrine: Diabetic Ketoacidosis (DKA), Hyperthyroidism, Thyrotoxicosis
5. In later pregnancy: Polyhydramnios, Pre-eclampsia, Onset of labor

Question 12

What tools are used to assess the severity of NVP or HG? (2)

Answer 12

1. Pregnancy-Unique Quantification of Emesis (PUQE): Assesses the severity of nausea and vomiting based on frequency and duration.
   Mild (≤ 6)
   Moderate (7-12)
   Severe (13-15)
2. HELP: Another tool to assess NVP or HG and/or treatment response.

Question 13

What are the key components of a patient’s history assessment for NVP? (12)

Answer 13

1. Previous history of NVP/HG
2. Quantify severity using assessment tools
3. Nausea, vomiting, ptyalism, and spitting
4. Inability to tolerate food and fluids
5. Effect on quality of life and daily activities
6. Self-reported nutritional status or rapid weight loss
7. Co-morbidities like epilepsy, diabetes, HIV, psychiatric conditions
8. Abdominal pain
9. Urinary symptoms
10. Infection
11. Drug history
12. Chronic Helicobacter pylori infection

Question 14

What investigations are recommended for assessing NVP? (3)

Answer 14

1. Blood Tests: FBC, U+E+Cr, Blood glucose level, Liver function tests, Arterial blood gases
2. Imaging: Ultrasound scan
3. Urine Dipstick: To assess for ketonuria and other abnormalities

Question 15

What are the goals of treatment for NVP? (4)

Answer 15

1. Reduce severity of symptoms and improve quality of life.
2. Correct hypovolemia, ketonuria, and electrolyte abnormalities if present.
3. Prevent serious complications like vitamin deficiencies, electrolyte abnormalities, or weight loss.
4. Minimize potential fetal effects of maternal pharmacotherapy.

Question 16

What are the non-pharmacological management approaches for NVP? (10)

Answer 16

• Eat smaller amounts of food more often
• Prefer bland foods that are low in fat
• Avoid spicy foods
• Eat foods high in protein
• Don’t skip meals
• Avoid cooking or being in the kitchen if it triggers nausea
• Eat a few dry crackers or biscuits before getting out of bed
• Ginger (in any form)
• Drink eight glasses of water per day
• Carbonated drinks or ginger/peppermint tea

Question 17

What are the first-line pharmacological treatments for NVP? (7)

Answer 17

1. Pyridoxine (Vitamin B6) monotherapy
2. Thiamine (vit B1 to prevent wernickes encephalopathy in prolonged vomiting cases)
   Antihistamines
3. Doxylamine and Pyridoxine (Vitamin B6)
   Antiemetics
4. Promethazine
5. Chlorpromazine
6. Cyclizine
7. Prochlorperazine

Question 18

What are the second pharmacological treatments for NVP? (3)

Answer 18

• Metoclopramide
• Ondansetron
• Domperidone

Question 19

What are the third-line pharmacological treatments for NVP?

Answer 19

Corticosteroids

Question 20

What are the potential maternal complications of NVP? (10)

Answer 20

• Vitamin deficiencies (B1, B6, B12)
• Electrolyte imbalances
• Dehydration and Metabolic acidosis
• Mallory-Weiss tears
• Gastroesophageal reflux disease (GERD)
• Acute kidney injury
• Liver Dysfunction
• Thromboembolic Events
• Wernicke’s Encephalopathy
• Depression and anxiety

Question 21

What are the potential fetal complications of severe NVP? (6)

Answer 21

• Intrauterine growth restriction
• Low birth weight
• Preterm birth
• Small for Gestational Age (SGA)
• Developmental Delays
• Increased risk of miscarriage or stillbirth in severe untreated cases

Question 22

When should inpatient care be considered? (2)

Answer 22

If there is at least:
- Continued nausea and vomiting and inability to keep down oral antiemetics
- Continued nausea and vomiting associated with clinical dehydration or weight loss >5% despite oral antiemetics

Question 23

What inpatient care do you give? (7)

Answer 23

1. Assess and address ABCs
2. Begin with 2 L of RL over 3 hours to maintain a urine output of > 100 mL/hour.
3. Subsequent fluids up to 1 L every 4 hours for up to 3 days(ongoing assessment)
4. Electrolyte Replacement:
   Add Potassium Chloride: 20-40 mEq per liter of NS, adjusted as needed.
   Magnesium Sulphate: 1-2 grams IV over 1-2 hours for hypomagnesemia.
   Thiamine (Vitamin B1): 100 mg IV daily
   Correct other electrolytes based on based on lab results.
5. Providing psychological support to manage stress and anxiety.
6. Anti-emetics
7. Corticosteroids for refractory cases

Question 24

What monitoring do you do for admitted patients (3)

Answer 24

1. Vital Signs and Hydration Status
   Regular monitoring of blood pressure, heart rate, and urine output.
2. Laboratory Tests:
   Monitoring of serum electrolytes, liver enzymes, and renal function.
3. Nutritional Support:
   Enteral Feeding: NGT
   Parenteral Nutrition in severe cases where enteral feeding is not possible.