A year-long investigation into the Free Birth Society reveals how mothers lost children after being radicalised by uplifting podcast tales of births without midwives or doctors.

Lucy Hough talks to the investigative correspondent Lucy Osborne about her reporting.

The Free Birth Society (FBS) is a multimillion-dollar business that promotes an extreme version of free birth, meaning women giving birth without medical assistance. The Guardian can now reveal that the organisation has been linked to dozens of cases of maternal harm and baby deaths around the world. After a year-long investigation, Sirin Kale and Lucy Osborne explain why some women they interviewed found FBS’s views so appealing, and why medical professionals say their claims about birth are dangerous

• The Birth Keepers: I choose this – episode one

The Free Birth Society was selling pregnant women a simple message. They could exit the medical system and take back their power. By free birthing. But Nicole Garrison believes FBS ideology nearly cost her her life. This is episode one of a year-long investigation by Guardian journalists Sirin Kale and Lucy Osborne