Blake Lively claims her breasts increase in size ''throughout the day.''

The 'Age of Adaline' actress, who has three-month-old daughter James with husband Ryan Reynolds, says she has to change outfits several times to avoid suffering ''a wardrobe malfunction'' when she's away from her baby and doesn't have time to pump milk.

Explaining why she was spotted wearing 14 different ensembles in three days while recently promoting her new film in New York City, the 27-year-old star said: ''So my proportions definitely started to, shall we say, increase throughout the day. I walked out onstage for one appearance in an outfit that had fit perfectly when I tried it on many hours earlier, but by the time it got on me, I thought, 'Oh no! This isn't going to cover them up at all!' I was very worried about a wardrobe malfunction.''

Blake, who doesn't work with a stylist, began planning her press tour outfits in February and got her sister, Robyn, to help her try on more than 500 looks before selecting 256.

But she admits looking glamorous takes a lot more effort since she welcomed her baby girl.

Asked where she changed clothes, she told PEOPLE magazine: ''In the green room, in the car, in a ladies' room. The hair seems to be happening in the car a lot. My hairstylist Rod Ortega is a magician in a car.''