Cake Lingerie recommends your nursing bras be purchased about a month or so prior to your baby being born. Cake suggests a seamless nursing bras to start (about the 1st month), as your bust will fluctuate wildly as your body tries to regulate its flow of milk. Typically sized XS-XXL, they will accommodate your changing bust. The soft-cup or t-shirt bras, with or without flexible wire will be ideally suited about 4-6 weeks post birth when your bust fluctuations have somewhat stabilised. The Cake Nursing bras are ideal post birth, with each one fulfilling a specific purpose.