Health minister Dr Dan Poulter has written to NHS chief executives asking them to ensure new mums are treated with "dignity and respect".
NHS officials have faced criticism over the practice in recent weeks. Some parents are approached by promotion company workers while they are still on postnatal wards, Glasgow-based GP Dr Margaret McCartney said.
In an editorial, published on bmj.com at the end of May, Dr McCartney wrote that Bounty, which gives parents free Baby Bags, profited by selling parents' details to other companies. But she said the hours after birth were ''hardly an optimal time'' to obtain consent for giving out data.
Parenting charity NCT has previously raised concerns about Bounty representatives approaching mothers while they are on wards because they might think that they are being spoken to by an NHS official.
Child benefit forms are provided in the Bounty Baby Bag and HM Revenue and Customs pays £90,000 a year to the company to distribute the forms - even though they are available free online.
Writing an open letter to hospital bosses, Dr Poulter said: "Whilst it is beneficial to have accessible information available to women at a time when they are responsive to messaging, I am sure you will agree that it is unacceptable for parenting support organisations including Bounty to use this as an opportunity to collect private data and share it without the express informed consent of the parents."
Mumsnet co-founder Justine Roberts said: "Many parents will be encouraged that government is responding to concerns about the harvesting of data and hard sales taking place on NHS maternity wards. Mumsnet has written to all NHS Trusts asking them to review Bounty's access to maternity wards and we very much hope that trusts will listen to parents, as well as eminent health professionals and charities."
A Bounty spokeswoman said that the company was also writing to hospital trust chief executives. She added: ''We meet thousands of mums every day and treasure this special position and take our responsibilities very seriously. '99% of NHS hospitals choose to welcome Bounty on maternity wards and we visit over 2,000 mums every day." She added that 96% of mums choose to join the Bounty scheme.