Physiological skin changes during pregnancy 1, hyperpigmentation: nipples, areola, umbilicus, genitals and the midline of the abdominal wall are obvious; chloasma may appear; melanocytic naevi may increase in size and new pigmented naevi may appear. Hair and nail changes: hair growth is active, toenails become brittle and peel off at the distal end. 3, glandular changes: exocrine sweat gland secretion function enhancement appear prickly heat, hyperhidrosis; top secretion function decline; sebaceous gland function enhancement, areola gland enlargement. 4, connective tissue changes: stretch marks; skin tags; keloids. 5, vascular changes: spider nevus; palmar erythema; small hemangiomas; varicose veins and hemorrhoids; deep vein thrombosis; edema; gestational gingivitis, gestational gingivoma or gestational granuloma.