12/05/2017 09:30 BST | Updated 12/05/2017 09:30 BST

Love Makes A Family: Celebrating LGBT Families

'We don't always know how to describe everyone in our family,' says Jessica, whose friend Simon donated sperm to her and her female partner and welcomed them into his extended family. 'For instance, what do you call the mother of the wife of the man who helped you get pregnant?'

The theme of this year's International Day Against Homophobia, Transphobia and Biphobia (IDAHOT) - love makes a family - reminds us that people don't have to be legally or genetically connected to become a family. They can even, like Jessica, create family relationships that they don't yet have the language to describe!

When we interviewed more than 70 parents and children for our LGBT parenting guide, 'Pride and Joy', we found that new forms of family like Jessica's, are blossoming everywhere. We spoke to families which included donor-dads, co-parents, donors, surrogates, friends, birth families of fostered or adopted children and extended family members.

Some LGBT parents deliberately seek out friendships with other LGBT parents. When she was growing up, Bryony's mum and her mum's female partner had a close-knit group of friends who became like an extended family. She was always encouraged to look wider than her immediate family for love, support and to enrich her understanding of the world.

'I consider them very much as family. They have all had a massive influence on me,' Bryony says now that she is in her twenties. 'Our families are different to one another, but they are all different from the norm, and that is something we have in common. Knowing them has helped me to better understand my own family. The parents in all these families break societal norms in their own, individual ways and are happy being themselves. I suppose there is a culture that we feel we belong to.'

Sometimes such friendships end up becoming co-parenting or known donor arrangements. Jackie is a lesbian single mum who asked a straight male friend, Paul, to donate sperm to help her become a parent.

Over 20 years later their relationship still holds strong. 'If I made one good decision in my life, it was choosing Paul to be my son's father,' says Jackie. 'The relationship between them is phenomenal. It's everything I could have hoped for and more.'

Paul agrees: 'My decision to be a donor has always been rewarding. It was a profound way I could do something positively life-changing for a good lesbian friend, but at the time, it didn't feel as if it would be particularly life-changing for me. The thanks of a dear friend, and the arrival of a human being were, in themselves, reward aplenty two decades ago. But the myriad of additional rewards over the years have been wonderful too, particularly from being part of my son's life and seeing him become the person he is today.'

For Nicholas and Michael, a gay couple who became parents through surrogacy, their relationship with Sarah - their surrogate - and her husband and children became extremely close. 'We didn't design it that way, we didn't even know we wanted it,' says Michael, looking back.

'There's an obvious end goal when you are trying to get pregnant: the relationship you and your partner will both have with your baby. I expected that. What I didn't expect was that the relationship with Sarah and her family would be equally important. They have become part of our extended family. We've not just got a baby now, we've got these wonderful, special people in our life.'

When a child is adopted or fostered, their birth family may still be part of their lives. Adoptive or foster parents may have to manage contact between their children and their children's birth families, and to build their own relationship with the birth families. They are another way in which LGBT parents can find themselves part of unconventional family structures.

'There's lots of people in our lives who wouldn't be there if we'd had our own children,' reflects Jay, who has a foster daughter and an adopted son. 'We deal with two families who are not our own.'

Bryony, Jackie, Paul, Michael and Jay are just a few of the people who share their stories and advice in 'Pride and Joy' and who have found that their experience of family stretches far beyond the traditional nuclear family model, often in ways they did not expect themselves.

Of course, there can still be tensions and strains in these extended, unconventional families, like in any family. Making a family requires love and also requires hard work, generosity, understanding and a fair bit of give-and-take.

On 17 May, as we join thousands of people around the world to mark IDAHOT, we will be celebrating families of all shapes, sizes and definitions, and the love that makes them and unites them.