Makindo Medical Notes

Hyperemesis gravidarum is a severe form of nausea and vomiting during pregnancy. It is more intense than typical "morning sickness" and can lead to dehydration, weight loss, and electrolyte imbalances. It typically occurs in the first trimester but can persist longer in some women.

Incidence

• Hyperemesis gravidarum affects about 0.5-2% of pregnancies.
• It is more common in first-time pregnancies and in women carrying multiples (twins, triplets, etc.).

Symptoms

• Severe nausea and vomiting, leading to an inability to keep food or liquids down.
• Significant weight loss (more than 5% of pre-pregnancy body weight).
• Dehydration: dry mouth, reduced urine output, and dark urine.
• Electrolyte imbalances: dizziness, lightheadedness, and muscle cramps.
• Fatigue and malaise.

Risk Factors

• Multiple pregnancies: Higher levels of hormones like hCG can trigger more severe symptoms.
• Previous history: Women who had hyperemesis in a previous pregnancy are more likely to experience it again.
• History of motion sickness or migraines: These conditions may predispose women to hyperemesis gravidarum.
• Hydatidiform mole: A molar pregnancy can cause elevated hCG levels, leading to severe nausea and vomiting.
• First-time pregnancies: Women pregnant for the first time have a higher risk of developing hyperemesis gravidarum.

Complications

• Dehydration and electrolyte imbalance: Prolonged vomiting can lead to significant fluid and electrolyte disturbances.
• Malnutrition: Inability to eat or absorb nutrients can cause malnutrition, affecting both the mother and fetus.
• Weight loss: Excessive weight loss may impact fetal growth and increase the risk of low birth weight.
• Wernicke’s Encephalopathy: Rare but serious complication due to thiamine (vitamin B1) deficiency, caused by prolonged vomiting.
• Psychological Effects: Hyperemesis can lead to stress, depression, and anxiety in affected women.

Diagnosis

Hyperemesis gravidarum is diagnosed based on clinical symptoms and ruling out other causes of nausea and vomiting, such as gastrointestinal infections or thyroid disease. Key factors for diagnosis include:

• Persistent vomiting, not related to other medical conditions.
• Loss of more than 5% of pre-pregnancy body weight.
• Signs of dehydration, such as decreased skin turgor, dry mucous membranes, and hypotension.
• Laboratory tests may reveal:
  • Elevated hematocrit due to dehydration.
  • Low potassium and sodium levels indicating electrolyte imbalance.
  • Elevated ketones in the urine (ketonuria) due to prolonged fasting and fat breakdown.

Management

Management of hyperemesis gravidarum is focused on relieving symptoms, preventing dehydration, and correcting nutritional deficiencies.

• Lifestyle and dietary modifications: Small, frequent meals that are bland and easy to digest may help. Avoiding strong odors or triggers that worsen nausea can also be beneficial.
• Rehydration therapy: IV fluids are often required to correct dehydration and electrolyte imbalances, especially when oral intake is not possible.
• Antiemetic medications: Medications used to control nausea and vomiting include:
  • Pyridoxine (Vitamin B6) and doxylamine (safe during pregnancy). Doxylamine is a first-generation antihistamine which selectively binds H1 receptors in the brain; pyridoxine (vitamin B6) is a water-soluble vitamin.
  • Ondansetron (Zofran), although safety concerns have been raised regarding its use in the first trimester.
  • Metoclopramide and promethazine are also used to control symptoms.
• Nutritional support: If oral intake is insufficient, nutritional supplementation through enteral feeding (nasogastric or percutaneous tube) or, in severe cases, parenteral nutrition may be necessary.
• Thiamine supplementation: Thiamine supplementation is recommended, especially before administering IV glucose, to prevent Wernicke’s encephalopathy.

When to Admit

• Intractable vomiting not responding to oral medications.
• Severe dehydration or electrolyte imbalances.
• Significant weight loss or malnutrition.
• Signs of complications like Wernicke's encephalopathy (confusion, ataxia, visual changes). Give Pabrinex

Prognosis

Most women with hyperemesis gravidarum experience improvement in the second half of pregnancy, although some symptoms may persist. With proper management, the prognosis is good, and most women go on to have healthy pregnancies and deliveries. However, long-term psychological effects may require attention.

References

• RCOG: The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum
• NHS: Hyperemesis Gravidarum