Kate Middleton's sister arrives at Prince Louis' christening in an elegant outfit

Duchess Kate’s younger sister, Pippa Middleton chose an elegant dress for her nephew’s christening on Monday. She broke away from wearing cream-colored dresses, opting for a light blue choice.

A

video showed the expecting mother in all her glory. Her baby bump was barely visible in her pleated knee-length dress.

On Monday, Pippa Middleton, 34, attended her baby nephew, Prince Louis’ christening. She celebrated the little boy’s big day while carrying her own first child.

Duchess Kate’s younger sister is expecting her first child with husband James Matthews this October. She arrived with her family in the afternoon at Chapel Royal, St James's Palace for the special event

For more on this story go to our Twitter account @amomama_usa. Middleton looked amazing in a light blue custom dress by Italian designer Alessandra Rich.

She accessorized her elegant outfit with a matching hat, clutch, and heels. On her head, she wore a matching baby blue hat with ribbon and netting detail.

The dress featured a structured and paneled middle which cinched Middleton in at the waist. It was custom-made for Kate's younger sister for the occasion.

The hem came to just below the knee and it featured heavy pleating detail with sheer material that showed off her toned legs underneath. The dress was designed with buttons that ran down the length at the front.

It was designed to look old-fashioned but with a modern, chic twist; as it featured long sleeves with puffed detail above the wrist. Middleton kept her makeup simple with just a hint of blusher and nude lipstick.

She broke away from her trend of wearing cream-colored dresses to the Royal christenings of her sister’s children. In 2015, at Princess Charlotte's christening, she wore a long cream dress with a fascinator.

While at Prince George's christening in 2013, she wore a mid-length cream coat-dress with her hair in a low ponytail. She accessorized with a flower fascinator:

In a column for Waitrose Kitchen, Middleton recently opened up about her first trimester. She revealed that she did not battle severe pregnancy sickness, or Hyperemesis Gravidarum (HG), unlike her sister Kate.

Last September, Kensington Palace announced that Kate was pregnant with her third child and noted that she was once again battling HG. This was the same illness she battled when she was carrying Prince George.

The sickness rendered Kate unable to perform her Royal duties during the first few months of her pregnancies.