Kate Middleton
Kate Middleton's blue dress that she wore to attend an official engagement in Kensington on 19 January, has sparked speculation about her baby's gender. Clarence House

There is much speculation about the gender of Kate Middleton's baby, at least in the media if not in the royal family.

Fresh reports now suggest that the Duchess of Cambridge may know about the baby's gender and that she is hinting at it by wearing blue dresses to her royal engagements.

A report in US-based fashion and popular culture website, The Gloss, refers to Kate's recent engagement in Kensington where the Duchess opened a leisure centre built on the site of a 1970s pool where Princes William and Harry learned to swim.

Kate wore a pale blue coat to the occasion. The £195 Natasha coat from the Seraphine maternity label definitely sparked speculations that Kate is pregnant with the brother of Prince George, according to the report.

And as Kate took off her blue coat, another dress in shades of blue could be seen.

In fact, Kate Middleton has been wearing blue dresses since her early pregnancy days.

The 33-year-old Duchess, who is due in late April, wore a chic pale blue Jenny Packham dress to attend the Wildlife Photographer of the Year Awards at the Natural History Museum in October.

This was also Kate's first public appearance in 11 weeks after she recovered from hyperemesis gravidarum, the severe morning sickness that had also struck her when she was pregnant with Prince George.

Kate Middleton
The Duchess of Cambridge attends the Wildlife Photographer of the Year 2014 Awards ceremony at the Natural History Museum in London in October. Clarence House

In November, Kate Middleton accompanied Prince William to Valero Pembroke Oil Refinery in Wales, where she donned a baby blue coloured double-breasted trench coat by Matthew Williamson.

Kate's blue ensembles have surely allowed royal watchers to speculate that the Duchess is carrying a boy but the royal couple have not opted to know the baby's gender.

In Kensington, the Duchess clearly told an admirer that she did not know the baby's gender yet.

"I told her [Kate Middleton] I hoped it was a girl but she said she doesn't know yet. She said it was moving around a lot," a well wisher, Martina McDonagh, said.