Baby boy for Collette Dinnigan - Sydney Morning Herald

Fashion designer Collette Dinnigan has given birth to a baby boy, named Hunter. Excited friends say the couple is "over the moon". Photo: Damian Bennett

Bringing the perfect finale to a long journey, iconic Australian fashion designer Collette Dinnigan gave birth to a healthy baby boy - Hunter Desmond David Dinnigan Cocks - at the Mater Hospital, Crows Nest, Sydney, on Monday.

The baby boy arrived weighing in at four kilograms, in a ‘‘really surprisingly, fabulously normal delivery’’ with his proud dad, Bradley Cocks, and big sister, Estella, waiting close by. His second name, Desmond, is a nod to Dinnigan’s Irish yachtie father, Des, while his third name, David, is after Bradley’s father.

Excited friends told Fairfax the baby was ‘‘healthy’’ and ‘‘so gorgeous’’ and that Dinnigan, 47, was absolutely elated with the safe delivery. ‘‘There was no drama, it was a natural birth and very quick and everyone is over the moon.’’

The designer, one of the industry’s biggest names and the first home-grown designer invited to show in Paris, had made no secret of how thrilled she was to be adding to her family, telling how her eight-year-old, Estella, was ‘‘beside herself’’ at the impending arrival.

‘‘We are absolutely thrilled,’’ she said in the lead-up to the birth. ‘‘We are just looking forward to this baby arriving!’’

While Dinnigan ultimately conceived naturally, she has refused to become the poster girl for post-40 pregnancy.

The fashion luminary has been open about the harrowing journey it took to conception, which included several IVF treatments, and warned others against leaving it too late, saying she thought she was invincible in her 30s.

‘‘There’s a perception out there that so many fabulous Hollywood stars in their 40s are having children,’’ she said when she announced her pregnancy.

‘‘I have so many friends who are trying to have children and they can’t. It’s your body’s natural clock. You’re not meant to have children in your 40s and 50s.’’

Dinnigan, a vegetarian, has been glowing and relaxed in the past few years since meeting hotelier Cocks, 35, in 2009. The couple eloped with Estella to wed in a picturesque magenta bougainvillea-clad ceremony in the seaside Italian village of Positano in July last year.

‘‘We might just be very, very lucky,’’ she says. ‘‘We are thrilled. You can’t expect to have a child at this age. We’re blessed.’’