The scientific undertones of this thread are interesting and over the years I have happened upon a few related items. None of them are very controlled photographic studies of breast growth, however I am sure that it has been done somewhere before.
* The first example I recall was a series of B-W photos taken of a father and daughter each year for around 20 years starting around 1945. The interesting thing is that they start when she is an infant and the father has her in an adult swimsuit, the same suite, every time. The poses are only slightly related each time but what I remember from the text were the comments from the lady saying that by the end it was a just something to humor her old dad. She also did not like getting into a 20 year old swimsuit. The dad had used her mom to guess at her final size. These were family photos and innocent with no indecent intent, but they were cool. That suite did look old by the last photo, when she was an average looking 20-21 year old.
* I have seen at least 5 different time lapse pregnancy clips on the net. If you dig enough you can still find some. Two clips came from a BBC special about 2000-01 where they did follow a very tolerant couple as they documented her physical changes over the months. They had her naked on a treadmill and morphed between small segments. Both segments were focused on her belly, but her chest was substantial. If you dig on Atom Films you can turn up "60 seconds to Sophie" or something like that. Again, a tribute to the wonders of pregnancy but a good bit of perseverance on the part of the couple. In all of these the breast changes are secondary. Except for the Sophie slip these were all Real Media files which I do not like and do not keep around, sorry.
* Last, is the only breast focused time lapse loop that I have seen (see attached) and it is a gif file "found" by Al_Inflatcha a while back. It came, he said, from one of those "pill" sites now down. I can not say how real it is but this is the only thing in all my archives.
Good hunting, cause I know this stuff is out there...