The hypokalemic paralysis is a disease characterized by the development of acute muscular weakness, associated to low levels of blood potassium (< 3.5 meq/L). Here we present two cases: in the first one, a 23 years old woman, with 15.5 weeks of gestation has a cuadriplegia associated to blood potassium level of 1.4 meq/L, diagnosed with distal tubular acidosis; she required mechanical ventilation for respiratory paralysis. The medical profile remits with potassium intravenous replacement and the pregnancy ends with a spontaneous abortion. The second case is a 15 years old woman with 26.5 weeks of pregnancy, who suffers a generalized paralysis with blood potassium of 2.7 meq/L, requiring also mechanical ventilation for respiratory paralysis; the final diagnosis was Barterr syndrome, and the medical profile remited after potassium supplement. Her pregnancy got complicated with a severe preeclampsia, enough reason for interrumpting the pregnancy at 29.1 weeks of gestation. In both cases Guilliain-Barre syndrome was ruled out.