What to wear to a royal wedding when you're in your last trimester? For Victoria Beckham, the answer is a frock that is pleasantly understated. The mama-to-be modified one of her Fall 2011 runway looks, creating a navy blue sheath that just graced her growing belly. The swing style is a nice departure from the form-fitting styles we usually see, and best of all it's comfortable! Here are four options for expectant moms looking to re-create the look.

From top left: ASOS Maternity Frill Sleeve Swing Dress ($54), Isabella Oliver Pocket Dress ($209), ASOS Maternity Layered Sleeve Shift Dress ($62), Fierce Mamas by Christian Siriano for Moody Mamas Maternity 'Abigail' Dress ($98).