The Royal Palace announced that the second baby of Kate Middleton and Prince William is expected to arrive in April 2015.

Middleton's pregnancy was announced in September and she is now around fourteen weeks pregnant, according to an official statement.

However, the 32-year-old duchess continues to be affected by hyperemesis gravidarum, a condition that is thought to be caused by elevated levels of pregnancy hormone or human chorionic gonadotropin (HCG).

The condition causes severe vomiting, and may lead to dehydration, weight loss and a build-up of ketone in the blood or urine, called ketosis.

The Duchess of Cambridge also suffered from the same condition while pregnant with her first baby, Prince George, who is now a one-year-old.

Middleton was hospitalized with hyperemesis gravidarum and severe dehydration during her first pregnancy.

However, this time around it seems that Middleton's doctors are better prepared.

"Don't be fooled by the fact that she hasn't been admitted to hospital this time. She is just as poorly. The difference is that her doctors have been able to diagnose and treat her quicker. She really hasn't been at all well, though," a source said.

Middleton joined Prince William on Tuesday to officially welcome Singapore's President Tony Tan as he begins a four-day visit to the UK.

The Royal Palace did not reveal the upcoming baby's gender, but rumors suggest that it is going to be a girl.

Sources have confirmed that the reason why Middleton and Prince William were so ecstatic when they were leaving the clinic was because Dr. Alan Farthing confirmed to them they were having a daughter, a report mentioned.