Abstract
Acute increases in blood pressure of pregnant women must be regarded and treated as preeclampsia, for if the patient really has preeclampsia it may progress in severity and lead to eclampsia or even death. In collecting cases for the study of preeclampsia the working diagnosis cannot be accepted; far more rigid criteria must be used because hypertension is common to several other unrelated disorders. Erroneous diagnoses lead to erroneous conclusions. Examples cited concern (A) the renal distal tubular reabsorption of free water during osmotic diuresis in hydropenia, (B) the concept that preeclampsia causes chronic hypertension in women who otherwise never would have developed it, and (C) the concept that higher levels of the mean arterial pressure in the second trimester (MAP-2) predict preeclampsia. Many women bearing the diagnosis of mild preeclampsia really have transient hypertension, which appears to be latent essential hypertension brought to light by pregnancy. Transient hypertension often 1s predicted by higher levels of MAP-2; it had a high rate of recurrence in later pregnancies and often predicts ultimate chronic hypertension.