Lena Dunham auctioned off the 'Madame Ovary' sweater she wore while attending the Planned Parenthood Los Angeles Champion of Choice event on Thursday (01Oct15) and had to leave in a loaned coat.

The Girls actress/writer turned heads when she turned up in the wool sweater designed by her boyfriend Jack Antonoff's sister - because it featured an image of the reproductive system.

Dunham shared the look on Instagram, adding the caption: "Rollin to the @plannedparenthood Los Angeles Champion of Choice event and there was only one sweater that would do."

And the fashion choice was such a big hit, people wanted to buy it from her.

Offering up the sweater during a charity auction, Dunham was amazed when it went under the hammer for $4,000 .

She returned to Instagram later and wrote, "The @plannedparenthood event in LA tonight was so crazy inspiring. I also spontaneously auctioned the ovary patterned sweater off my body for a nice 4k to benefit PP... Had to walk home in my skivvies (underwear) and a men's coat."