In pregnancy- there is hyperplasia of the Thyroid, Parathyroid, Pituitary and Adrenal Cortex Although the size of thyroid gland increases, patient remains euthyroid. Basal metabolic rate increases  There is hyperinsulinemia during pregnancy (due to insulin resistance) so as to ensure continuous supply of glucose to fetus.Skin changes during pregnancy During pregnancy, skin undergoes varying degrees of pigmentation, which varies among individuals. The dark line running centrally below the umbilicus is called the lineanigra. Chloasma: It is hyperpigmentation of the skin around the cheeks, forehead and eyes. The pigmentation is thought to be due to increased levels of endorphins and melanocyte stimulating hormone and disappears spontaneously after delivery