Beyonc on cover of Vogue's September issue, and reveals her twins were delivered by emergency C-section

Beyonc, who appears on the September cover of U.S. Vogue, reveals she had an emergency C-section when she delivered her twins last year.

The singer, in a series of essays in the magazine, saidshe was 218 pounds and was swollen from toxemia. The 36-year-old saidthe babies spent many weeks in intensive care and her husband, Jay-Z, was "such a strong support system."

She saidshe put pressure on herself to lose weight in the three months after the birth of her first child, Blue Ivy. But after the twins, Rumi and Sir, she approached things differently.

Beyonc saidshe has a "little mommy pouch" and is in no rush to get rid of it.

The superstar also saidit's important for her to help open doors for younger artists. Her photo is the first Vogue cover to be shot by an African American photographer, Tyler Mitchell, 23.