During pregnancy, your breasts will increase one full size or more in both the cup size and the rib band measurement. This may be shock enough for new moms anxiously awaiting their first born, but the growth after giving birth can be mind-blowing. Between 48 and 72 hours after birth, your breasts will increase at least one additional full cup size or more while your breasts fill with milk. Most women are astounded at their breasts' unending ability to grow, but rest assured, the boob stops here. Your cup size expands, but your rib cage starts to shrink back to your pre-pregnancy size or very close to it.
Nursing bras are specially-constructed to support your swollen breasts and offer quick and easy access for breastfeeding. Consider approaching a store that specializes in nursing bras and ask them to show you what's available and if needed, fit you for a proper bra. A professional fitter can introduce you to the different fasteners and styles of nursing bras and help you make the appropriate choice. Don't worry, most professional fitters are used to the leaks and tenderness of newly filled breasts—nothing will shock them.
Nursing bras are available in several styles: with or without underwire and with or without flaps. Nursing bras with underwires usually provide good support. The underwires are a soft, flexible plastic, rather than hard wire. You should never sleep in a bra with an underwire; you don't want the underwire putting pressure on your breasts which can lead to blocked ducts and mastitis.
If you didn't wear bras with underwire before you started nursing, there is no need to start wearing one now. Nursing bras without underwire will be more comfortable, especially if you're not used to underwires. Women with larger breasts may find that bras without underwire don't provide enough support and lift—you don't want your bra straps digging into your shoulders.
For your breastfeeding convenience, many nursing bras are made so the fabric covering the cups of your bra can be easily detached without having to undo the bra. These bras are designed for quick and easy nursing. Flaps may connect at the top of the bra cup or between the cups near the band of the bra. Try out both types of clasps and choose the type that you can clasp and unclasp with one hand—quick and easy.
If nursing bras with flaps have too much of a peek-a-boo nature for you, you can find nursing bras that easily pull to the side with one hand. These bras are usually made of softer fabric so they can be pushed aside easily. Most are very comfortable to wear and sleep in. Like nursing bras without underwire, if your breasts are larger or quite heavy with milk, these bras may not offer the amount of support you will need to be comfortable.
Most nursing bras are made of cotton; some are made of nylon or polyester. Cotton bras are soft, wear well, and wash easily. Stay away from synthetic fibers; they won't feel very nice on tender breasts and they will keep your breasts warm which can be a breeding ground for bacteria.
To make sure you have some extra room in your cups, bring a breast pad along when trying on nursing bras. Breast pads absorb errant milk so you don't have to walk around with the tell-tale wet circles on your chest. You don't want your perfectly fitted nursing bra to feel tight when you shove a breast pad in there.
Breast milk will soak through your breast pads at some point during your breastfeeding days. When you find a nursing bra that you like, buy more than one. You will always have one drying on your shower rod waiting for laundry day, so it is good to keep a spare or two.
Nursing can make you feel pretty bovine on a good day. You want a soft nursing bra that is supportive, but still nice to look at. A pretty nursing bra will lift your spirits on those days you wonder if your breasts will ever fit in a nice bra again. Buy at least one really pretty nursing bra that you like to look at. Matching panties wouldn't hurt either.