If the number is uneven, round up to the next even number. This is the band size. Determining Bust Measurement and Cup Size Measure around the fullest part of the bust. Make sure the tape fits evenly and doesn't slip down the back. Subtract the Band Size from the Bust Measurement.
Some women can expect one last cup size increase immediately postpartum.
Often after 10-12 weeks of nursing women will return to their prenatal bra size. Tops and dresses are cut fuller through the bust line and hips giving you the room where you need it. Hemlines are cut longer to the front, so the more you show the more your hemline evens out. If you are lucky enough to be carrying twins or more, please go up a size.