Bra Fitting During Pregnancy

During pregnancy your abdomen and lower rib cage will increase in size to allow for the growth of your baby. This will cause the band measurement (right underneath your breasts) to increase during pregnancy, from the first trimester onwards.

Your breasts start changing in preparation for feeding a baby early after conception. Women often find their breasts are tender, and this may be your first indication that you are pregnant. Your breasts are likely to increase about one cup size during the first trimester.

Bra fitting in the first trimester

Firstly, take a measurement under your bust, making sure the tape measure is firm against your rib cage.  This will give you your band size. If the number is an odd number, round up to the next even number.

Secondly, take a measurement around the fullest part of your bust, again making sure the tape measure is firm around your body.  The difference between your band size measurement and this measurement will give you the cup size.

For example, if your under bust measurement is 32 and your bust measurement is 37, you have 5 inches difference between those two measurements, so I’d suggest that you are around a 32DD in size.

Cup Size Difference in inches
A 1
B 2
C 3
D 4
DD 5
E 6
F 7
FF 8
G 9
GG 10

However, you then need to make some adjustments to that sizing:

  1. Ensure your maternity bra is fitted firmly on its tightest fitting so that there are hooks for you to expand the bra as your rib cage increases in size. This usually means that you should increase your band size by one measurement (i.e. increase from a 32 to a 34 band).
  2. If you increase your band measurement by one size, then you should decrease your cup size by one to keep the cup size the same in both band sizes (i.e. 32DD becomes 34D). If you keep the cup size the same in both band sizes, then the cup size will also be bigger in the larger band size.
  3. Ensure your breasts are fully covered by the bra cup to support your growing and changing breasts. A deep centre on the front of the bra is a good guide to ensure a fuller cup. Even if this is a style that you’re not used to you, may find it more comfortable with heavier breasts.
  4. Ensure the fabric is not pressing on any breast tissue. Check the top of your breast and under your arm especially.
  5. Choose a soft-cup bra rather than one with a wire – with your body and breasts constantly changing, a wired bra may fit well when bought, but may not fit in a couple of weeks time!
  6. Get re-fitted/checked regularly during your pregnancy to ensure the bra is supporting your breasts, especially if you choose to wear an underwired bra or if you feel uncomfortable in the bra you’re currently wearing.
  7. If there is a large difference in breast size between left and right, fit the larger breast and use a soft filler in the smaller cup to even up the look. Differences in breast size are often accentuated during pregnancy.
Bra fitting in the second trimester

You should measure yourself as described above, still wearing your bra on a tighter fitting as your ribcage will continue to expand through to the end of your pregnancy.  It’s important to make sure that your breasts are still fully covered by the cup and that the bra is not pressing onto any breast tissue.  It’s often in the second trimester when you start to develop a ‘bump’ that your normal bras will start to feel uncomfortable.

Bra fitting in the third trimester

If you have got to the third trimester still wearing your normal bras, then they will definitely start to feel uncomfortable now! Depending on how early in the third trimester you are, you may want bras that will last you through to breastfeeding, so I’d recommend buying a seamless bra that comes in generic sizing, rather than a more structured bra with specific band and cup sizes. Your rib cage will still expand up until around 37 weeks, so make sure that you allow a bit of room in your band size to allow for this continued growth.  You should also be aware of the cup size, especially if you are planning to use this bra for breastfeeding as you need to make sure that there is room in the cup for when your milk comes in.

If you are 36+ weeks pregnant, then you should be thinking about buying your nursing bras at the stage.  Please read Bra Fitting for Breastfeeding which gives more detailed information about measuring yourself at this stage of pregnancy.

This information is only a guide and every bra will fit differently. If you want to talk through how your bra is fitting, about how your body is changing during your pregnancy, or you need advice about what size or style bras you need, then please contact me, I’m here here to support you!