Breast Augmentation Sizing
First of all I personally have found that clinical photos or if available 3D imaging of your breast to determine your optimal size is far more accurate than "sizing with implants" as the type of bra/ holder makes this method somewhat inaccurate. I started with that system 25 years ago and moved on to photos over the last 15 yrs and glad I did..
Although swelling occurs at the time of your period, for the vast majority of women it is only a fraction of a cup size.
Breast Implant Sizing and timing related to menstrual cycle
To some degree it does not matter because your breasts will likely continue to change after surgery and will continue to vary with your cycles. Just be aware that whatever size you choose will range in a similar fashion.
Size and operate on your breasts when you are not on your menses
Rita, it sounds that you are like many women, who experience PMS effects on the breast (i.e. engorgement, tenderness, and slight swelling). Given that history, I would recommend that you try to determine the size implants when you are less tender, usually the week after you stop your period. Although the implant base size will not change, as this is predicated on the width of your chest wall, the amount of overlying breast tissue may seem tighter, when you're off your period. So while it's unlikely that you will choose an implant which is 100cc larger, you might choose one, which is 20-30cc larger.
With regards to operating on the breasts while a woman is on her menses, it doesn't matter for some individuals. However, if you are sensitive and reaching for nonsteroidal anti-inflammatory drugs (Motrin, Advil etc) to combat cramps, it is likely that you will experience more pain, nausea and potentially bruise more. Good luck.
Breast Implant sizing is best when your breasts are at baseline
Size your implants when your breasts are at their baseline volume--not when they are enlarged around the time of your period. Regardless, I always recommend that you choose the largest implant that might fit your goals best. I rarely hear women say, "I should have gone smaller." On the contrary, the opposite refrain--"I wish that I were a half-cup-size bigger"--is much, much more common.
Timing the sizing around your menstrual cycle is probably not necessary. Your breast size should not change significantly at different stages of your menstrual cycle.
Not sure if you need to be this concerned about when to size your breasts. Do the sizing when you are at your baseline and take it from there. This is really not a science but an art and you need to look at it as such otherwise you will be disappointed with the final outcome. Plastic surgery is an art and no matter how much you try to turn it into a science it will turn out to be an art.
So size your self whenever, the differences can not be that much.
Breast augmentation sizing during or before menstruation
Breast Augmentation is not aviation or civil engineering and the amount of detail you are demanding is more than a bit of over kill.
Reason - the current volume of your breasts + volume implants placed in a bra will ALWAYS give you an OVERLY optimistic (too large) result than the volumetric contribution these implants will make when compressed by your skin and breast tissue OR your skin, breast and muscle tissue over them.
Let's ASSUME that your breast is slightly engorged pre-menstrually. The Amount of transient breast swelling when added to the mix will NOT make much of a difference in the choice of your implant.
Personally, I would encourage you to choose an implant based on the amount of coverage your breast can provide. Within these parameters, pick the lightest / smallest implant you can live with (less weight - less drooping) with the guidance of your Plastic surgeon. In this way, period - no period, you will get the best. most naturally appearing breast augmentation.
Breast implant sizing is not influenced by menstrual cycle
The small changes in the breast during a normal menstrual cycle should have very little impact on eventual implant size used in augmentation. Most often there is a slight firmness or tension in the breast, still these same changes will go on after augmentation. Breast size is an individual choice limited by the characteristics and personality of your breast, and your goals in augmentation. If you work carefully beforehand with photos, try bras, and communicate your choice clearly to your surgeon, the proper implant can be chosen at the time of surgery to give you the result you hope for. Where you are in your cycle should not matter.
Best of luck,
Timing of breast implant sizing
You are micromanaging this and the truth is that it really doesn't matter at all when you size the implant and when you do the surgery. Also, you can't build your surgery schedule aroung people's menstrual cycle bceause the stress of upcoming surgery can shut the hormonal process down or alternatively can accelerate it.
Breasts are engorged and larger during the week before you start your period.
The best time to assess breast size is the week AFTER your period, when your breasts are at "baseline" size. Of the possible times you mention, while you are menstruating would be best.
We also avoid doing elective breast surgery during the week before the patient's period, because the breasts are engorged (more blood supply) and there is more bleeding during surgery.