When Is Duchess Kate Middleton's Baby's Due Date?

(Photo: REUTERS/Andrew Matthews)Kate Middleton and Prince William will soon add a third baby to their growing family.

Prince William and Princess Kate are officially welcoming their third child this spring.

On Tuesday, the Kensington Palace released a statement announcing the date Kate is due to give birth. "Their Royal Highnesses The Duke and Duchess of Cambridge are delighted to confirm they are expecting a baby in April," reads the official statement from the palace (via PEOPLE). Additionally, it was announced that the royal couple will be starting 2018 with an official royal tour of Sweden and Norway.

Kate and William confirmed in September that they are expecting baby no. 3, who will join their kids Prince George, 4, and Princess Charlotte, 2.

The past month has been a struggle for the Duchess of Cambridge, as she was confined to the walls of Kensington Palace due to a serious form of morning sickness known as hyperemesis gravidarum. Kate seems to be doing much better after she debuted her baby bump in a public engagement last week.

Meanwhile, Kate made an unexpected public appearance on Wednesday with husband William and brother-in-law Prince Harry. The brunette beauty channeled Princess Diana's polished style with her blue jacket and skinny black pants.

She joined William and Harry in honoring the 150 graduates of Coach Core, a program the three of them founded to help young adults train and become sports coaches and mentors.

Us Weekly reports that Kate and William want to leave the gender of their baby a surprise this time. As of now, they are busy working out the other preparations for their heir's April arrival. A source revealed that Kate's OB-GYN, 54-year-old Alan Farthing, has postponed his retirement to deliver the couple's new baby.

A suite in the exclusive Lindo Wing of London's St. Mary's Hospital has also been reserved to give the royal family privacy once Kate gives birth.