Final answer:
Several skin changes can occur during pregnancy, including stretch marks, spider veins, varicose veins, chloasma, and acne flare-ups.
Step-by-step explanation:
During pregnancy, several changes can occur in the skin. These changes include the development of stretch marks, spider veins, varicose veins, new freckles, darkening of moles, and acne flare-ups. Additionally, around 75% of pregnant women experience chloasma, which is the appearance of blotchy brown patches of skin on the face. These skin changes are primarily due to hormonal fluctuations during pregnancy.