Lewis and Jauch got married in July 2019 at Sting’s estate in Tuscany, Italy, in front of 180 friends and family members, including Sugababes singer Keisha Buchanan and The Voice winner Jermain Jackman, who sang at the ceremony.
Jauch, who is a German-born creative director, shared the same picture and message on his Instagram account.
Lewis announced her pregnancy on Instagram in March by sharing a photo of her in a black bodycon dress showing off her baby bump.
She captioned the post: “Can’t wait to meet you in the Summer.”
Friends and famous faces sent messages to the singer, congratulating her on the new arrival, with Michelle Visage, Dancing on Ice winner and radio presenter Sonny Jay and singer Jessie J all commenting on her Instagram post.
Lewis won the third series of The X Factor in 2006 and went on to achieve success with singles including Bleeding Love, Run and Better In Time.
In 2016 she replaced Nicole Scherzinger as Grizabella in the Broadway revival of Cats.