A new type of family hovers just below the radar of statisticians and Government departments. High divorce rates, declining marriage rates, extended childbearing years and more liberal attitudes in general are contributing to the emergence of households headed by a mother whose children have been fathered by different men.

The road to full status as a card-carrying member of the multi-dad club is typically paved with events often beyond the control of the mothers - accidental pregnancies, failed marriages, brief love affairs, uncommitted fathers and relationship breakdowns.

The resulting family tree resembles the complexity of an overgrown jungle. Trying to work out who does what and sees who on Christmas Day can result in fallout of atomic proportions. The stakeholders in such a tribe include: the children, the ex-partners, the present partner, the extended family, the present in-laws, the ex-in-laws - and maybe even the present partner's family from a previous relationship.

The term multi-dadding was coined by British journalist Lucy Cavendish, a mother of four children by two different fathers. In her Observer article, Cavendish describes multi-dadding as a modern phenomenon and lists some high-profile British multi-dadders, such as Sadie Frost, Ulrika Jonsson and (the late) Paula Yates. In our part of the world, Lucy Lawless, Sally Ridge and Wendyl Nissen happily navigate their way through multi-dadding arrangements.

Compared with the exotic family configurations of Angelina Jolie and Brad Pitt, or Madonna and Guy Ritchie, their family units are reasonably mainstream.

But in the suburbs, where an unconventional family blend can still raise an eyebrow, attitudes can be judgmental. Mt Wellington mother-of-four Rhiannon Anderson, 30, has to regularly steel herself for what she calls "the look" when people ask if her children, who all have different skin colouring, have the same father.

"I still find it extremely rude and I would never do it to anyone. And I'm always so mortified," she says. "Generally I say: 'It's none of your business'. Or if I'm feeling like I'm up for 'the judgment look', I say: 'No, they have four different fathers'."

And even though derogatory comments aren't made directly to her, she occasionally overhears people gossiping about her family situation - and she senses general disapproval from members of the public.

"Sometimes it annoys me. It annoys me that these people aren't in my house bringing up these four children as best as they can yet they can pass judgment," Anderson says. "But most of the time that's just the way it is. You kind of expect it. I mean no one's going to think it's absolutely fantastic that you have multiple fathers for your children."

Women like Anderson say the negative reaction towards multi-fathered families comes from an assumption that multi-dadding women must be promiscuous.

But Anderson is quick to set the record straight, saying she has only had relationships with four men - the fathers of her four children.

"I'm classed as highly fertile. All my children have been conceived while I've been on birth control." She calls her 4-year-old son Tarquin "my miracle baby" because she was using four different types of contraceptives when he was conceived.

Andrea Colledge, 30, of Rotorua, who has two children to two different fathers, works hard to make sure both her relationship with her present partner, Andy Munro, and with her ex-partner Mike Butler, work well.

Witnessing friends' broken relationships turning nasty, Colledge vowed that would not happen to her. Her son Keenan, 6, would be the one to suffer if her relationship with his father broke down, she says.

She and Munro have a 1-year-old daughter, Chloe, together. "I guess we all just treat it like one big happy family," she says. "What's the point of drama?" As far as Colledge is concerned, there's no room for animosity.

"Basically, we're just friends and we co-parent our son. We both respect each other and we respect what we need to do for our son. I want him to have a really good relationship with his dad. Andy's like a dad to him but he isn't his dad, which probably makes it a bit hard on Andy but he understands," she says.

"I just want Keenan to be happy. He looks forward to going to [his] dad's. He looks forward to coming home. There are no mind-games or poison or anything like that."

But it's not always that easy. According to University of Auckland professor of sociology and author of 15 books, Maureen Baker, research suggests multi-fathered families have a higher probability of problems than any other kind of family, including single-parent families.

The increase in multi-dad families is a result of higher rates of separation and divorce, she says, rather than a woman's choice. "People don't set out to be multi-dad families."

According to Baker "rates of cohabitation and having children outside marriage have been going up since the 1990s and there's a very high rate of break-up among people who cohabit without being legally married".

But she doesn't think the numbers are high.

"If we're talking about having three and four different children from different fathers, we're probably talking about 1 per cent of the population at most."

While Statistics New Zealand recognises "there have been significant changes in the way that families are formed, dissolved and reformed" there's a lack of comprehensive data on the establishment and breakdown of de facto relationships, subsequent re-partnerships and the formation of step-families that are often precursors to multi-dadding situations.

Jan Pryor, in her work for the Wellington-based Roy McKenzie Centre for the Study of Families, notes that step-families are less stable than first partnerships, thus opening the way for the cycle to readily recur.

Single mothers typically face financial challenges when raising a family, and fiscal problems are only heightened when a series of different dads have been and gone, leaving their offspring behind.

Solo-mother Jane Bold, 51, of Tauranga, had two children to each of her three ex-husbands. She knows firsthand how tough it is to raise a large family created by different men.

"My third husband took on four kids plus two of his own. It just made things really hard. That's the main reason we broke up. A lot of it was financial. We just couldn't make ends meet," Bold says.

With only her two youngest children, Chris, 17, and Matthew, 16, at home, she is still struggling. She collects the DPB and pays $330 a week towards a mortgage. "I'm usually on the bare bones of my bum. I've got HPs coming out my ears. I realise that's my choice but that's the way our lives seem to work now," she says.

"I look at my respective husbands and since they haven't been with me they're all doing quite nicely, thank you. It pisses me off, it really does. And here's me pretty much the same as I was in my 20s."

Hand-in-hand with multi-dadding is a notional revolving door through which the men enter and leave at will. Bold's two eldest daughters, Terena, 29, and Lisa, 25, have seen three consecutive father-figures bail.

"Having respective fathers walk out the door has probably impacted on the kids," she says. "My kids have been through far more than kids should ever have to go through."

A disenchanted Bold has sworn off men for good now. "I will never marry again and I will never have another man in my life," she says.

Rhiannon Anderson can see a positive side to the extended families that her children belong to. "Outsiders might find it odd that the children have four sets of grandparents and two mums and three dads," she says.

"I think they feel really secure that there are a lot of people around them who just accept them. There's just a whole bunch of nansies and popsies, and nannas and poppas."

However she adds a cautionary note. "You'd have to be insane to pick this life. It would be so much easier just to have mum, dad and the kids."

It may not be all white picket fences and utter conformity but there's a warmth and inclusiveness that perhaps could put some plain old vanilla-flavoured families to shame.

Two of Anderson's children have been informally adopted by two of the fathers: 8-year-old Haidee by the father of her eldest (Malachi, 11), and Tarquin, 4, by Damien - Anderson's current partner, with whom she lives, plans to marry and who is the father of her youngest child, Isis, aged 1.

Damien's introduction to the household was something of a baptism by fire. Initially they just dated, going to movies and dinners; she didn't introduce him to the children until she realised it was serious.

It took Damien, a fancy-free bachelor with no dependants, a while to acclimatise. "He's still adjusting to being in a family and having children around," she says. Today, he's the family's main income earner. "We live on Damien's wage - poor guy," she laughs.

Ironically, for a wholeheartedly contemporary phenomenon, an underlying contributing factor to multi-dadding is an idealistic belief in the old-fashioned fairy tale of settling down with a man, that this relationship is the one that won't turn to custard. Certain that this time it's true love, the woman seals the deal with a pregnancy and - surprise, surprise - their supposed knight in shining armour heads for the hills.

As Anderson explains, "You get into a relationship and you really want it to work. You think this must be it." Then along comes a baby, followed by stress and a break up.

So having children to different fathers isn't the classic happy ending. It's not exactly the stuff of girlhood dreams. And, as the mothers themselves admit, it's far from a perfect scenario.

Anderson's partner Damien has suggested that another baby (which would be her fifth child) might be a nice idea. Despite the occasional testing moment her multi-dadding lifestyle engenders, she has retained her sense of humour. "I said to him that it's not in my nature to have another child with the same man. I might have to find someone else."