The Interdisciplinary Alliance for Children (IAC) has prepared a briefing paper to lobby MPs ahead of the second reading of part two of the Children, Schools and Families Bill next week.
The IAC, which counts the National Children's Bureau and NSPCC among its members, argues children will be reluctant to disclose abuse if expert reports can be reported openly, making it harder to safeguard children effectively.
It is opposing any changes before there has been an independent assessment of the impact on children of the government's proposals.
The media have been permitted to attend family court hearings since April 2009.
Part two of the Children, Schools and Families Bill proposes to relax the rules on what can be published by the media.
Alison Paddle, ICA spokeswoman, said: "The pressure to make everything accessible to the media in family courts will actually harm children and their interests.
"If a child is wanting to talk to a mental health practitioner or paediatrician about abuse they have suffered, they may well be put off if they know it can be disclosed in court or over the internet to everyone.
"Children hate having the details of their life spread out in public
