Is there a gender size gap for children's clothing?

Strides have been made recently in the bid to breakdown gender stereotypes within children’s toys and clothing, with many retailers moving away from the traditional pink for girls blue for boys way of presenting kids products.

But could there be a gender size gap within children’s clothing?

The debate has been fuelled after a Twitter user posted on the social media platform, asking why there was such a big difference in the sizing of Marks and Spencer PJs for a 3-4 year old girl compared to a 3-4 year old boy.

“Just wondering what you think the big difference between boys and girls is that you feel the need to size their clothes so differently?” the post read.

“Both sets of pyjamas in aged 3-4. Why such a difference?”

The poster wrote before adding the #everydaysexism #letclothesbeclothes hashtags.

The woman’s post was picked up by Let Clothes Be Clothes, allies of the UK campaign Let Toys Be Toys, which calls on retailers in the UK to stop limiting children to outdated gender stereotypes in the design and marketing of children's clothes.

Since then many others have joined the debate about whether girls clothes should be smaller than boys, with some saying making girls clothes smaller is a form of ‘sexism.’

READ MORE: Schoolboys allowed to wear shorts following protest in skirts

A spokesperson from Marks and Spencer did respond to the original poster’s concerns claiming that three year old girls are smaller than their male counterparts and as a result their clothes are reflective of this.

But Let Clothes Be Clothes also took to Twitter to point out that that store’s own sizing guides has children of both genders as the same size.

An M&S spokesperson has since responded to Yahoo UK’s request for comment, saying the following:

"We know customers want choice and so we sell a wide range of lengths, fits and styles in kidswear. In younger children we do work to the same size measurements and customers can access this information on our website.”

READ MORE: School uniforms in Wales will be gender neutral from September

Growth charts from the Royal College of Paediatrics and Child Healthcare (RCPCH) based on World Health Organisation (WHO) Child Growth Standards do appear to show a very slight difference between the weight and heights of boys and girls aged between 3 and 4, with boys being slightly bigger and heavier than girls but it is minimal.

According to Dr Sonal Shah, NHS GP and lifestyle medicine expert though boys genetically have evolved to be bigger than girls, things are changing with better nutrition and same opportunities for boys and girls.

“Yes boys and girls have different growth charts,” she explains. “They also have different growth spurts and rates of growth at different ages. It comes back to other hunter gather days, where men went to hunt.”

She also points out that some children girl or boy may be smaller than others due to their ethnicity.

“For example Asian baby's are overall smaller and some countries will have their own growth charts to reflect this,” she adds.