Here's some of what we've learned.
Our breasts begin to prepare with the release of hormones in the weeks before baby's arrival. It is in that time that we recommend getting out of underwires, but staying in a supportive bra, to allow for proper circulation. It is recommended you stay away from underwires until a strong, predictable nursing routine has been established, where baby is emptying the breast, usually by 8-12 weeks postpartum. Then it is safe to get into a *proper fitting* underwire nursing bra.
Many nursing brands offer a flexible underwire which isn't as stiff as metal. When this underwire fits snug against the chest and encompasses all the breast tissue, it can actually encourage better circulation. An ill-fitting nursing bra will not hold the breast up and away from the chest like it should, but instead will allow the breasts to sag, adding heat and pressure to the underside of the breast, and may restrict circulation. Especially with larger sizes, it is important to gently support all breast tissue, pulling it away from the chest, giving room for the fluids to circulate where they need to. And underwire will also help to separate the breasts, which is very important in larger sizes. This helps the skin to breath and support the tissues completely. It is also more comfortable than having your breasts squished together where they get hot and sweaty.
For those who prefer a non-underwire bra, there are many that offer the same support by having a structured heavy seam under the breast to offer the same benefits. However getting into the G+ cup sizes, women often feel like that is not enough. Or they will take a non-underwire bra for days around the house, and an underwire for the days they are out.
Coming in for a fitting in that last month before your expected due date will help you determine what styles work best for you. Ask to see as much as you can, and then you'll have an idea for after baby has arrived and you're ready for another bra.
Read more about When to Get Fitted During Pregnancy
For the week's between waiting for babys arrival and the months after, we recommend the Bravado Dream Nursing Tank, available to F/G cups and a 40 band, or the Cake Lingerie Cotton Candy Nursing Bra, available in sizes extra small to extra large.