What Happens

For the first few days after giving birth, when you breastfeed, your baby receives colostrum. At around the third day, your milk will ‘come in’. At that point, you can experience an increase of one or two more cup sizes from your third trimester.

Typically after about 6 weeks to a few months of nursing, these fluctuations settle down. You will have established your breastfeeding relationship and routine, and will usually decrease a few cup sizes. As well, around this point, your rib band size will begin to go back to your pre-pregnancy size. This is the size you will likely stay until you finish breastfeeding. That is, at about your pre-pregnancy rib band size, and up one cup size.

Find Your Current Size
If you’re not sure of your pre-pregnancy or third trimester bra size to use as a starting point, you can also measure yourself to determine your current size. Here’s how:
Measure yourself with your (unpadded) bra on. Stand straight, relaxed, with your arms down, breathing normally. If you can, measure yourself in front of a mirror, so you can make sure the measuring tape isn’t twisted and that it’s parallel to the floor all the way around.



How to measure for a nursing bra

1) Take Your Rib Cage Measurement – Just below your breasts. If you have someone helping measure you, and you are wearing a bra that your breasts are sagging in even a little bit, take your straps and pull up so that your breasts are lifted to where you would like them to be, and then have your friend measure your rib cage. This is a snug measurement.

2) Take Your Bust Measurement - Across the fullest part of your breasts. As with the previous measurement, if you are wearing a bra that doesn’t position your breasts exactly where you’d like them to be, then hold your bra straps up so your breasts are lifted to their ideal spot, and measure across the fullest part (usually across the nipples). This is a loose measurement.

Now, you are ready to determine your current size:
1) If you get an odd number on your rib cage measurement, round up. This is your rib band size.
2) Subtract that rib band size from your bust measurement. Every inch is one cup size:

•     1 inch = A cup
•     2 inches = B cup
•     3 inches = C cup
•     4 inches = D cup
•     5 inches = DD cup
•     6 inches = E cup
•     7 inches = F cup
•     8 inches = G cup
•     9 inches = H cup

Now that you have a good idea about your current size, you’ll need to look at what stage of pregnancy or nursing you are in right now, and what you are buying the bra for to make sure it will work for your current and future needs. Refer above to the breast changes you can expect during pregnancy and nursing, and adjust accordingly. For example, if you just measured yourself in your third trimester, you will want to keep that band size, and go up 1-2 cup sizes for a nursing bra to fit you well when your baby is born.

Things to remember when measuring for a nursing bra

• Purchase your nursing bra as near to your due date as possible (36+ weeks). By then your breasts should have   reached their maximum size. You will need two or three to cope with leaks.
• Keep your bra on when measuring.
• Ask somebody else to take your measurements.
• Pregnancy can distort your measurement.
• Consider your current bra size - are the cups too small?
• Is the underband comfortable?
• Remember that after the baby is born your rib cage measurement will decrease a little.
• Consider the fact that when the milk comes in your breasts may increase slightly – perhaps by a cup size. Once a feeding pattern has been established, re-measure and change your nursing bra accordingly. Also bear in mind you will probably use breast pads to soak up leaks – so allow enough room for these.

When to measure for a nursing bra?

When is the best time to measure for a nursing bra?

Mums are advised to get professionally fitted for their nursing bra at approx 36-38 weeks. At this stage, breasts have often grown to their approximate nursing size.