Hyperemesis Gravidarum

While morning sickness can occur in up to 70% of all pregnancies, it is usually more troublesome than serious. The more severe and disturbing condition, hyperemesis gravidarum, may complicate up to .3% of pregnancies, causing physiological changes that may effect the mother and fetus. Maternal weight loss, dehydration, electrolyte imbalances, acid-base disturbances leading to renal and hepatic injury have all been reported in extreme cases. Persistent vomiting can lead to Mallory-Weiss tears and nutritional deficiencies may lead to Wernicke’s encephalopathy.  

Prematurity, low birth weight and a slight increase of central nervous system and integumentary malformations have been reported in fetuses of mothers affected with hyperemesis gravidarum. An increase risk of testicular cancer in male patients of mothers with hyperemesis gravidarum during their pregnancy has also been reported in the urology literature.  

Hyperemesis gravidarum should be considered when all other causes of persistent nausea and vomiting have been ruled out. Pyelonephritis, pancreatitis, cholecystitis, hepatitis, appendicitis, gastroenteritis, peptic ulcer disease, thyrotoxicosis, and hyperthyroidism can present in similar fashions, with intractable nausea and vomiting, and are treatable conditions. Late presenters need also to be ruled out for HELLP syndrome and other causes of hepatic and central nervous system dysfunction.  

The etiology of hyperemesis gravidarum is not well understood. Hormonal causes related to human chorionic gonadotropin, estradiol(Drug information on estradiol), progesterone(Drug information on progesterone), adrenal hormones and pituitary hormones have been proposed, but currently there is no conclusive evidence implicating any specific substance. Psychological and social factors influence this disease, such as in unwanted pregnancies, although this syndrome is not limited to unwanted pregnancies. Young, unwed mothers whom are felt to have "sinned" and therefore harassed by their parents, are common sufferers of this syndrome. Remarkable improvement with hospitalization is often noted in such cases, with rapid relapses once released to the home environment. Hysterical and immature personalities can predispose one to this condition. 

The diagnostic work-up must always start with confirmation of a viable, intrauterine pregnancy. Gestational trophoblastic neoplasia can present with hyperemesis gravidarum in up to 30% of cases. Electrolytes, liver function tests, thyroid function tests, creatinine, blood urea(Drug information on urea) nitrogen, urinalysis and a complete blood count are some of the studies that need consideration in the work-up. 

Once the diagnosis is made, treatment consists of mainly supportive care. Intravenous fluid, up to 5 to 6 liters per day using the appropriate amounts of sodium, potassium, chloride, lactate or bicarbonate, glucose and water, are primarily used in correcting the hypovolemia, electrolyte and acid-base imbalances, and ketosis,. Until vomiting is controlled, these patients should be maintained as NPO. A low dose, continuous infusion of an antiemetic, such as promethazine(Drug information on promethazine), can have beneficial effects. Vitamins, including thiamine(Drug information on thiamine), can be added to supplement the intravenous fluids. Patients should be maintained NPO for at least 48 hours after all symptoms and vomiting have ceased, to prevent rapid regress. Initiate PO intake with neutral fluids and a small, bland, dry, carbohydrate diet, in frequent intervals. Avoid noxious stimuli such as unpleasant odors. Reassurance and emotional support is important at this time, and psychological counseling can be initiated once symptoms have abated. 

Patients with intractable, prolonged vomiting may be treated with nasogastric enteral feedings, peripheral parenteral nutrition, or total parenteral nutrition. Rarely is interruption of pregnancy necessary. 

Oral medications have long been the main stay of out-patient treatment. Until forced off the market Bendectin (pyridoxine-vitamin B-6 (10mg) and doxylamine(Drug information on doxylamine) succinate (10 mg)), a category B medication, was efficacious and safe for both mother and fetus. This formula can be reproduced over-the-counter using Unisom Nighttime Sleep Aid (25 mg) (not Maximum Strength Unisom Sleepgels, which contains diphenhydramine(Drug information on diphenhydramine) hydrochloride) one half tablet and Vitamin B-6 (25 mg) one half tablet, each in the morning and afternoon, and one tablet each at bedtime, as needed. Useful category C medications are prochlorperazine(Drug information on prochlorperazine), promethazine, trimethobenzamide, and droperidol(Drug information on droperidol)., although because of their category designation, informed consent should be obtained on all patients treated with the above medications.