Melanin deposits on the neck during pregnancy may be caused by increased estrogen secretion or by ultraviolet radiation. The former can be gradually recovered after 3 to 6 months postpartum, while the latter can be recovered in 3 to 6 months after taking sun protection measures. 1. The increased secretion of estrogen during pregnancy will have a stimulating effect on melanocytes, leading to an increase in melanin secretion, which is manifested as melanin deposits on pregnant women’s nipples, areolas, vulva, neck and other parts of the body, which is a normal phenomenon and can generally fade away 3~6 months after delivery. 2. If women do not pay attention to take sun protection measures during pregnancy, ultraviolet light long-term direct radiation on the neck, can also lead to melanin precipitation, usually takes about 3 to 6 months to return to normal skin color, but the recovery process needs to be taken to prevent sun protection measures, to avoid tanning again, if necessary, through the drug, or photorejuvenation and other medical treatments to lighten the melanin pigmentation. The darkening of the neck during pregnancy is a normal physiological phenomenon, do not be overly nervous, can wait for the delivery of the natural subside, and at the same time need to pay attention to take sunscreen measures to avoid long-term ultraviolet radiation caused by melanin deposits.