Hyperemesis Gravidarum

Description

Extreme nausea and vomiting of pregnancy is a clinical condition termed Hyperemesis gravidarum . It is a specific clinical diagnosis and is a condition of unknown cause. It is a finding of extreme nausea and vomiting in early pregnancy which leads to one or more of the following findings: weight loss of 5% or greater, ketosis, electrolyte imbalance (usually hypokalemia), central nervous system symptoms such as disorientation or actual seizures, and hepatic or renal damage. These latter three symptoms are rarely seen today and were reported in instances of neglected cases at the turn of the century. At the turn of the century, the maternal mortality approached 25% from hyperemesis gravidarum. This was prior to the time that fluids and electrolytes could be administered to correct the underlying problem in these patients.

Symptoms and Signs

The symptoms of hyperemesis gravidarum being in the first trimester and usually end by mid-pregnancy. However, there are a number of reported cases which have lasted throughout the entire pregnancy. The condition is more common in black patients as well as patients with multiple gestations .
Of note is the fact that patients with a previous pregnancy history of hyperemesis have about a 30% risk of recurrence in a subsequent pregnancy. These patients also are more likely to have gestational trophoblastic disease and they also are more likely to have a history of intestinal symptoms in response to stress. It is interesting to note that the rate of hyperemesis gravidarum is not dependent upon the parity status of the patient.

Diagnosis and Treatment

The hallmark laboratory findings in these patients is that seen in any patient with starvation ketosis. Specifically, there will be the presence of ketones in the urine. They are usually hemoconcentrated with elevation in their hematocrit. Their BUN and creatinine may also be slightly elevated. Their 24-hour urine output is decreased due to the dehydration and the urine is concentrated. It is important in the evaluation of this disorder to rule out other causes for their severe nausea and vomiting. Other intestinal causes such as gall bladder disease, pancreatitis, liver disease and infectious diseases of the GI tract must be considered.
Hyperemesis gravidarum is therefore, a diagnosis of exclusion .

The treatment of hyperemesis gravidarum is directed towards correcting the fluid and electrolyte imbalance which the patient has. These patients have usually been placed on outpatient treatments of antiemetics. However, they are unresponsive to these measures. Their treatment requires admission to the hospital in most cases. A balanced electrolyte infusion of such fluids as 5% dextrose and 1/2 normal saline are given at a relatively rapid rate initially to replace the hypovolemia. Laboratory studies including a CBC, electrolytes, screen of liver functions, urinalysis and spot check of the urine for ketones should be instituted. The patients are weighed daily and this serves as a valuable endpoint for the adequacy of fluid replacement as well as nutrition. Accurate I & O's should be recorded and these patients usually require potent antiemetics such as the phenothiazine derivatives, at least initially, to control their symptoms. These patients are unable to tolerate any oral nutrition initially. However, once the vomiting subsides, usually within 24 hours, they can be started on frequent small meals of clear liquids. As they tolerate these liquids, the diet is gradually increased and the patients are usually discharged to be managed on an outpatient regimen of antiemetics.

Approximately 1/3 of all patient who have an episode of hyperemesis gravidarum requiring admission to the hospital will require re-admission for the same condition. The relapse rate is therefore, very high. There are rare patients who have required total parental nutrition throughout their entire pregnancy in order to supply adequate nutrition because of the refractoriness of the hyperemesis. In patients with extreme malnutrition due to the hyperemesis, there is some potential for adverse effects on fetal growth. There are also sporadic reports of impaired neurologic outcome in infants born to mothers with hyperemesis gravidarum. The etiology of this adverse neurologic outcome has been suggested to be due to either the profound nutritional deficiencies or the extreme ketosis that the mother suffers.

The information in this page is presented in summarised form and has been taken from the following source(s):
1. Robert J. Blaskiewicz, M.D. Clinical Professor, Department of Obstetrics, Gynecology and Women's Health, Saint Louis University, U.S.A.: http://obgyn.slu.edu/