As with all bras, finding the right fit can be a challenge. It is the same process as with standard bras, the band under your bust should sit flat across your back not riding upwards. Avoiding any cutting in on your breast tissue is important. Bras which are too tight can restrict the flow and amount of milk produced – so it is important to change to to a Maternity/Nursing bra after you feel like your non-maternity bras are uncomfortable and no longer fitting or offering the right support. You may find your cup sizes change as your pregnancy progresses, every pregnancy and woman is different, however you may find you need to go up 3-4 cup sizes and increase your band size as your baby grows. Further changes can occur during the nursing cycle, when your milk flow comes in you may increase in the cup size before your bust size settles again. This great video can help you check if you have the right size.
What makes for the “best” nursing bras? Simple, Nguyen says: “If it fits, if it’s comfortable, if it’s easy to nurse in and you like the style.” No matter what you decide are the best nursing bras for you, Brown suggests picking up two nursing bras for daily wear (so you’ll always have one on hand when the other is in the wash) and one to sleep in. Keep in mind, Brown adds, “It's not unusual to change bra sizes within the first few weeks of breastfeeding”—so, if you’re shopping before baby arrives, consider buying one or two sizes larger than usual, so you have one ready to wear after birth.