Facebook is delaying an Instagram app for users under the age of 13.

Facebook said on Monday that it had paused development of an “Instagram Kids” service that would be tailored for children 13 years old or younger amid questions about the app’s effect on young people’s mental health.

The announcement comes ahead of a congressional hearing this week about internal research conducted by Facebook, and reported in The Wall Street Journal, that showed the harmful mental health effects Instagram was having on teenage girls.

Facebook said it still wanted to build an Instagram product intended for children that will have a more “age appropriate experience,” but was postponing the plans in the face of the outside criticism.

“This will give us time to work with parents, experts, policymakers and regulators, to listen to their concerns, and to demonstrate the value and importance of this project for younger teens online today,” Adam Mosseri, the head of Instagram, wrote in a blog post.

Facebook has argued that young people are using Instagram anyway, despite age-requirement rules, so it would be better to develop a version more suitable for them with more parental controls. YouTube, which is owned by Google, has released a children’s version of its app.

But since it became public that Facebook was working on the app earlier this year, the company has faced criticism from policymakers, regulators, child safety groups and consumer rights groups. They have argued that it hooks them on the app at a younger age rather than protects them from problems with the service, including child predatory grooming, bullying and body shaming.

Opposition to Facebook’s plans gained momentum this month when The Journal published a series of articles based on leaked internal documents that showed Facebook knew about many of the harms it was causing. Facebook’s internal research showed that Instagram, in particular, had a negative mental health effect on young people, especially young girls, even while company executives publicly attempted to minimize the app’s downsides.

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