It seems like my rib cage is bigger now. Is that possible?

If you’re noticing it, it’s not only possible, but probable.

This — like your bigger feet — is caused by the effects of the hormone relaxin. Relaxin’s job is to help loosen your ligaments (bone-to-bone connectors) so your rib cage can expand as your baby grows, and your hips can stretch as needed to birth your baby.

Late in pregnancy, you may have noticed that your baby was taking up valuable real estate under your ribs, thereby making the rib bones spread. Your chest will probably be pretty sore as it happens — not to mention baby’s kicks in that region can be quite painful. (Sometimes you will have a sore spot for years. No joke.)

And it’s not only the little one pushing the rib cage out: your vital organs have been smooshed and moved around to accommodate junior, too. Since you have had a lot of pressure pushing on your ribs (think of what it looks like when you freeze a can of soda) and sometimes they just stay expanded.

You’ll probably first notice the extra breathing room because you will have suddenly gone up a bra size — like from a 34B to a 36B or C. The letters represent the cup size (and that increase is due to other factors), but the number is from measuring around your rib cage. Of course, the change isn’t all due to bone changes — there’’s probably a bit of baby fat, too.

Where you’ll end up in terms of bra size, nobody knows for sure. Our advice is to get bra hook expanders or buy bras with hooks you can adjust as needed.