The days of locking women away to "serve out" their pregnancy in confinement are a thing of the past, as are the hideous shapeless tents that turned the beautiful female form into miniature replicas of the Titanic. Now, we live our lives practically without concession for our pregnancy, going out dancing (albeit much more slowly for most of us), to dinner, swimming, walking and about our normal daily lives right up until the birth of our children. Your Maternity and/or Nursing bra needs to be able to support your breasts properly throughout your still active life and throughout the changes that they're going through.
Underwire: For the most part it is not recommended for maternity bras or nursing bras to have an underwire. If you are still early on in your pregnancy this may not matter so much, but as your breasts get larger, the underwire can cause pressure on the milk ducts and lead to painful swelling. This danger is exacerbated after the baby is born when your breasts swell and shrink as you feed your baby. In worst case scenarios, the pressure from the underwire can lead to the excruciating mastitis.
Size: For many women, the need to change to maternity bra or nursing bra begins as early as four months pregnant. While it's possible to forgo upsizing your bra, having the right support can make the difference to back and neck aches, uncomfortable tightness causing swelling and stretch marks and sagging after your baby has finished feeding. Keep track of how your bra feels, and consider a new one (or set) if yours is too tight and constricting.
Versatility: For many women, there are important activities that don't stop just because we are pregnant or nursing. These include sleep (if you're lucky), exercise and the very occasional outing to a posh restaurant. For many women it can be much more comfortable sleeping with a bra on than off, and it's even more imperative that you have a well-fitting bra when you exercise than ever when your breasts are suddenly (in the scheme of things) much larger.
Look: It's a sign of the times that the maternity bras and nursing bras now come in as many different looks as a regular bra. If you're opting to purchase a few bras, then it may be worth looking at one or two that have that sexy look. Sometimes just having nice, comfortable underwear is enough to help you along if you're feeling a little blue pre or post baby.
Fold away cup - look for a bra that is versatile and will last you a while. Often maternity bras will have the fold away cup that is used when feeding. Try and choose a bra where the whole, or most of the cup folds away so that there is reduced pressure on enlarged and sensitive breasts.
How many? It's a good idea to have at least five bras. While you're pregnant and after you've had your baby, your breasts may leak and you may have to change them more often than usual. You'll also need differing levels of support and structure for different activities such as sleeping or exercise. Having a number of different styles ensures you will always be supported properly.
It's fairly likely that most women who are pregnant will need more than one "size up" in their bras. Take the time to reexamine your needs when you buy each bra or set of bras to make sure you get the most out of them. Don't skimp on them, they can make the world of difference to your pregnancy and nursing experience.