Women with conditions that might be influenced by this factor, such as a cardiac or renal impairment, warrant careful observation when estrogen-alone is prescribed. 5.13 Hypocalcemia Estrogen therapy should be used with caution in women with hypoparathyroidism as estrogen-induced hypocalcemia may occur. 5.14 Exacerbation of Endometriosis A few cases of malignant transformation of residual endometr