Your breasts will declare that you are pregnant long before your abdomen does. They are likely to feel slightly sore and swollen at first; the earliest sensations are similar to those you may be used to feeling in the second half of your menstrual period, only stronger. Then the buxom look of pregnancy begins. And your breasts are noticeably larger. Breasts typically increase one-cup size during the first trimester, and another one during the rest of the pregnancy. (The most dramatic increase in breast size will occur between two and four days postpartum when, due to the surge of milk-producing hormones and swelling in the tissues, your breasts seem to grow overnight!) Breast changes alone account for three pounds of your weight gain during pregnancy. Small-breasted women will notice these changes more, and first-time pregnant mothers may notice them more than they might in subsequent pregnancies. The tenderness in your breasts is most noticeable during the first three months and, like most discomforts of pregnancy, is less bothersome after the first trimester.
What Causes Breast Changes? Breast changes are caused, as you might expect, by a surge of hormones that stimulate the growth of milk glands and increase the blood flow to the breasts in order to nourish these glands. As the hormones are doing their work, you may notice throbbing sensations throughout your breasts. Your breasts may feel tingly, sore, warm, fuller, or more sensitive to touch. You may experience occasional shooting pains in your breasts that occur off and on for five minutes. You'll probably notice that your areola enlarge and darken, and that the tiny glands on the areola that secrete lubricating, antibacterial oil become more noticeable, resulting in a bumpier look. The veins on your breasts may also become more noticeable, like rivers and tributaries branching out over your breasts to deliver increased blood.
Although the rest of your body will eventually return to normal after pregnancy, your breasts will never be quite the same. They will acquire a different shape, going from your previous upward curviness to maternal, soft, global fullness. You may keep a bit of the buxom look you have while you are breastfeeding, or your breasts may actually seem smaller than you remember being. Bear in mind that these changes are due to pregnancy, and will occur whether or not you opt to breastfeed. Be kind to your breasts during pregnancy. Enjoy the comfort of frequent, warm showers and a breast massage if that helps. If you are concerned about sagging, you can help the skin and muscles around your breast tissue by wearing a supportive bra throughout your pregnancy (even at night if you need it.