For a nursing mom, ensuring good milk production is an important goal. While there are plenty of things that can impact your milk supply -- from the timing of feedings to medications you're taking -- your bra is unlikely to be a primary cause of poor milk supply. However, choosing the wrong bra may lead to discomfort and possibly other problems, so you'll want to pick a comfortable, supportive nursing bra to use while you're breastfeeding.
Breast milk production is based on supply and demand, so a decrease in milk is typically associated with a baby who doesn't feed frequently enough. In general, most women can make enough milk for a nursing baby, and women throughout history have been able to successfully nurse twins and other multiples without running out of milk. Certain medications, crash diets and medical problems can sometimes impact milk supply, so talk to your doctor or lactation consultant about ruling out other problems before blaming your bra, if you feel your milk supply isn't keeping up with your baby's needs.
Underwire bras are sometimes blamed for poor milk production, but there's no evidence that they actually reduce milk supply. However, wearing an underwire bra or extremely tight bra could block a particular milk duct and cause a plugged duct, leading to a painful buildup of milk in that section of the breast or an infection, according to AskDrSears.com. For most women, occasionally donning an underwire bra won't cause problems, but it's best to stick with a soft nursing bra for everyday wear.
Nursing bras are designed to support your milk-filled breasts without being too constricting. They typically have flaps that let you open the front of each bra cup so that you can nurse discreetly without removing the bra entirely. Because your lactating breasts may change shape and size over the course of your breastfeeding experience, you may need nursing bras in several different sizes.
The type of bra you choose won't affect the shape or size of your breasts after you stop breastfeeding, so there's no need to use a tight or ultra-supportive bra to prevent later sagging. The condition of your breasts after breastfeeding is actually determined by heredity and by how much your breasts changed in shape and size during pregnancy, says AskDrSears.com.