Tingling like pins and needles in the breasts during pregnancy may be caused by breast hyperplasia, increased breast fat, and changes in hormone levels. 1. Breast Hyperplasia: Breast Hyperplasia causes glandular cells to proliferate, which results in the growth of the entire breast, so the increase in size will stimulate the nerves, and therefore the tingling sensation will occur. 2. Increase in breast fat: During pregnancy, breast fat will increase, the expansion of the breast is affected, there will be local tension, and the increase in tension will cause pain. 3. Changes in hormone levels: After pregnancy, estrogen increases in the body, and at the same time, the mammary ducts will develop and spread again, and the level of progesterone is increased, which promotes the growth of mammary follicles, thus leading to the phenomenon of breast pain and tingling. Women with severe breast pain after pregnancy are advised to go to the hospital for examination to identify the cause and treat the symptoms in a timely manner.