The world's first test-tube baby paid tribute to her parents' bravery today - saying they stepped into the unknown by having her. Louise Brown, 35, was born at Oldham General Hospital on July 25 1978 after her parents Lesley and John became the first people to successfully undergo in vitro fertilisation (IVF). Her birth attracted controversy, with religious leaders expressing concern about the use of artificial intervention and some raising fears that science was creating 'Frankenbabies'. Tribute: The world's first test-tube baby Louise Brown, left, and her sister Natalie with their sons Aiden and Aeron both 15 weeks. They planted a tree in memory of their parents John and Lesley at Bourn Hall, Cambridgeshire, today
@highlight
Lesley and John Brown were the first people to successfully undergo IVF
@highlight
Daughter Louise, now 35, born at Oldham General Hospital on July 25 1978
@highlight
Birth attracted controversy and media attention from around the world
@highlight
Lesley died in 2012 aged 64, with John dying several years earlier
@highlight
Tree planted in their memory at Bourn Hall, Cambridgeshire, where IVF techniques were developed
Her sister Natalie, who was the first IVF baby to have a child, gave birth to her fourth child, @placeholder, in August.