Hypokalemia due to persistent vomiting during pregnancy.

Vomiting occurs in approximately 50% of all pregnancies. Vomiting of pregnancy varies in degree of severity from the so-called morning sickness, or nausea, to the pernicious, or severe, type that may end fatally. Although the majority of cases of vomiting of pregnancy fall into the mild or self-limited group, there is a small percentage of cases in which constant and persistent vomiting develop and result in loss of weight, dehydration, and ketosis. There may be, in addition to the well-known syndrome of hyperemesis gravidarum, vomiting associated with other etiological factors. During the past several years, the importance of potassium deficiency in many clinical conditions has been reported. Studies by Darrow, 1 Randall, 2 Butler, 3 and others 4 of the fluid and electrolyte losses in many clinical conditions have led to the understanding that losses of intracellular potassium frequently occur and that these losses lead to increased morbidity and mortality.