How long do I have to sleep on my back after a breast augmentation?

Studies have shown that sleeping positions can affect the shape of your breasts, whether you have implants or not.  Typically, this is present with side sleeping and with how your arm on the 'down' side typically cups the breast.  Nevertheless, studies have also shown the dangers of not sleeping.  Because of this, I typically recommend to patients that they sleep on their back ideally, ... but, I allow patients to sleep on their side if they cannot sleep on their back.  I recommend a pillow to help make sure the patient does not turn onto their stomach and I also recommend switching sides if possible.  Stomach sleeping is definitely not recommended.  It can negatively affect breast shape, facial aging, and can also put the neck in poor positions and cause serious cervical issues.  

Hi, thank you for your question. Informed patients are always the best!
For people who sleep better on their side or stomach, this surgery may create a problem in getting good sleep. It is generally advisable to sleep on your back for 6-8 weeks after breast augmentation to prevent any unrealized deforming forces on the implant pocket during sleep that may manifest in an asymmetric shape later on.
Every surgeon has their own post-op regimen and I recommend that you follow your surgeon's guidelines. If you are unable to sleep while laying on your back, talk to your doctor. She/he may allow you to sleep on your side as early as 1 week post-op. 
Laying on your chest is typically not advised after breast augmentation and can be quite uncomfortable as well. 
I hope this answers your question. Good luck in your recovery process!

I prefer that my patients sleep on their backs for a month after surgery.  If you sleep on one side, you may displace the implant, cause bleeding, or have swelling on the down side.  It is a particularly bad idea to sleep on your belly after surgery.

I ask my patients to wait 6 weeks before sleeping on their side or stomach after a breast augmentation.

After breast augmentation, i recommend using surgical bra all the time and sleeping on back with head propped up for 6-8 weeks, very strictly not lying on their sides or tummy. This helps the implant to settle down in the place in its pocket. Sleeping on sides might lead to implant displacement to the sides and lying on tummy can again lead to implant displacement. Some patients find it difficult and uncomfortable sleeping on their back for such long duration and exercise can help them with this.

I always recommend my patients to sleep on their back for at least 4 weeks so the implants can heal properly and remain in the correct place. I also recommend sleeping in a specific post op bra for 3 months.