Duchess wore Séraphine Vanessa Dress in New York in December 2014. The $99.00 Turtleneck Maternity Dress is described on Seraphine as, “the Vanessa maternity dress is an elegant style for before, during and after pregnancy. Made in a luxurious Ponte Roma fabric, the little black maternity dress drapes beautifully in a graceful A-line cut. The turtleneck style and full-length sleeves make this the perfect layering piece for your sophisticated maternity clothes collection. Featuring a curved empire line that defines your waist – the Seraphine Vanessa dress is a timeless wardrobe staple, and one of our most sought after maternity dresses.”.