Ideally, have your bras fitted by a professional at a lingerie store. These cells, called acini cells, don't kick in to production mode before birth. By trimester's end, however, breasts contain colostrum, a fluid rich in protein, fat, vitamins, minerals, and antibodies that will make up your baby's first meals. With estrogen levels rising throughout pregnancy, nipple sensitivity also may increase. Clear, straw-colored colostrum may leak, though that's more common later.
Symptoms overlap, and it's very individual what happens and when.
Instead, daub the nipple with a warm-water compress to clean off the leakage, and pat or air dry. When the Cooper's ligaments that support the breasts stretch, they never return to their previous tautness. A supportive bra will minimize the gravitational drag of enlarged breasts on those ligaments. Consider changing to a form of exercise that involves less jarring motion, such as swimming, walking, or using a treadmill or exercise bike. By the end of pregnancy, each breast has 15 to 20 lobes, each consisting of a major branch of the alveoli on the interior end and a milk duct that narrows to an opening in the nipple on the exterior.