Ditto. I don’t consciously think, “Well, I’m going to bed, I better put my bra on,” but if I happen to be wearing one already, I probably won’t take it off. I’m a 36B, so I can get away with most of my bras not having underwire, but even on the ones that do, it doesn’t really bother me.
I wear cotton tanks with built in shelf bras. It’s enough support for me to feel secure but comfortable enough to sleep in.
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I dropped out of bra class once I’d mastered the trick of unfastening them with one hand but now I’m curious. What is the purpose of the underwire?
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I can’t imagine sleeping in a bra, I hate the feeling of the band around my chest. But I may be oversensitive, the fitters keep trying to stick me in a 32C but I refuse to wear anything that tight and wear a 34B. And I like to keep my good day bras nice, if I slept in one it’d get all sweaty…
The only time I’ve done it that I know of was for the first two or three months after my reduction surgery. I didn’t do it before, either, because my (relatively to me) gigantic bras were also gigantically uncomfortable (I’m really oddly proportioned) no matter what I did. Such fun, being poked in the armpits by underwires…it’s no wonder I now refuse to buy bras with them, but at a 36 B I certainly don’t need wires. And it’s weirdly difficult finding bras without 'em.
Underwires provide support, up to a point. I found underwires increasingly uncomfortable the farther away I got from a D cup. In a larger size, they can start to buckle and twist and that’s *really *uncomfortable. I need more than an itty-bitty wire to support the girls. Larger bras tend to be less cute and more major engineering projects. Cute, large, inexpensive bras are almost as rare as unicorns.
I’m with you. The first thing I do upon getting home is head to the bathroom to change into sleepy/loungy clothes, and that includes shedding the bra.
Not quite. From a structural standpoint, the underwire serves only to hold the fabric of the cup open and in shape. It prevents (or tries to prevent) the uniboob effect, when the sisters get together to chafe and sweat. The physical support of the breast is (or should be) provided by the band which runs under the breast and the shape of the cup. The straps do not support, they shouldn’t be taking the weight of the breasts at all, they’re just there to hold the top of the cup flush with the chest. If your straps are cutting into your shoulders or your breast tissue is oozing out under your cups, you need a tighter underband, not tighter straps. The underwires don’t support, they separate.
Divide and conquer - my motto for bras and toddlers.
I dated a woman for a while a few months ago who always wore a bra to bed, and said this was the reason. She was (and still is, I guess) in her early thirties, and wanted to keep her nearly perfect 36-C’s from sagging as long as she possibly could. I have no idea if there’s anything to this, but her breasts were truly awe-inspiring to behold (and be held :)), so I had no cause to complain. 
If for some reason I was sleeping in my clothes, sure–it’s uncomfortable but not horribly so. Generally though, lord no. I’ve had the damndest time finding ones that fit properly standing up, and I don’t see what it would accomplish to wear one to bed aside from digging the underwire further into your skin.
Like many of the other ladies, the first thing to come off when I get home is shoes , quickly followed by the over the shoulder boulder holder. I’ve always been busty and, for the most part, have slept without one unless I was having out of control PMS and it hurt to roll over on them.
As for wearing one to bed to prevent sagging? Whahuh? The supportive tissues are going to degrade no matter how much you try to prevent gravity from doing it’s work. :smack:
The bra comes off as soon as possible when I get home, and the only time I’ve slept in one on purpose was while nursing, in an attempt to keep the bed dry…but then just for the first 6 months. After that things became more manageable. Since I’ve lost weight, I’ve been able to wear an underwire…the Joe Boxer ones from K-Mart are wonderful…that is truly comfortable, but I still want it off as soon as possible. And now that my last child has moved out, I sleep in as little as possible as much as possible.
Lalala I can’t hear you!!! My pretties are going to stay perky forever!!!
Seriously though, I figure… can’t hurt, might help.
It’s just another way of keeping everything in place. It provides firmer support than just a band of fabric does. Most bras without underwires have shaping and stitching in place that serves the same purpose as an underwire, it’s just not as strong. And an underwire also helps the band stay against your ribs. The bigger your breasts are, the more likely they are to try and make a break for it, and one of those avenues of escape is underneath the band – or rather, making the band roll up and then they slip free. If you have an underwire holding the band against your ribs, then that’s less likely to happen. Also, and WhyNot points out, underwires help your breasts maintain their separate identities.
Think of an underwire as playing the part of the Constitution in the domestic politics of breast management: both supporting the rights of the states and preventing chaos from breaking out.
Count me in as part of the group that never wears a bra to sleep in. When I’ve taken naps while wearing one, one or both of my breasts fall out the top of the cups, which is not comfortable at all.
Ugh. All I can say is, ouch! Bras are a necessity during the day for those of us with ample boobage, but trust me, they aren’t generally comfy. It would be like wearing pantyhose or really tight undies to bed. All you can think is how nice it would be to get 'em off.
I like to go commando to bed. It’s just nice to air everything out.
Except when I’m on my period (wear pads, so underoos are of necessity).
Sleeping in the nude would probably be ideal. But then, I get cold…
That’s why I use lots and lots of blankets. 
I hear dopers are good at warming up beds too
When I was pregnant with Dweezil I started wearing a bra to bed because the boobage hurt a lot of the time, and the bra minimized floppage and maximized comfort. I should point out that the bras I wore were from Decent Exposures - i.e. obscenely comfortable. I do not think a more traditional bra style would have been nearly so comfy.
I continued wearing them for sleep while nursing, through my next pregnancy, and while I was still nursing Moon Unit. So basically I lived in those things 24/7 for something like 4 solid years.
Now? Hasn’t been necessary but I could see how someone might find the right style would increase comfort.
If the movie “Knocked Up” is anything to go by, evidently hot women love to wear lacy underwire bras while doing all sorts of things in bed!
Can I just chip in with a “Dear God in heaven – NO!” Like some others here, I find that one of the chief joys of getting home after work is the taking off of the bra. Sleeping in one??? Yikes!! No. Never. Even if I’m somewhere other than home, the bra is coming off ---- the rest of the clothes may stay on, but the bra ---- no! Never. Dear God, no.
Of course, I’m not particularly well-endowed. If it weren’t for the headlight issue, I probably wouldn’t wear a bra at all, ever. And I’ve not dealt with the nursing/leakage issue. So I don’t have the same experience as some of the others here. But, still — Yikes!! Bra to bed!!! NOOOOOOO!!!