It's a question nearly every couple grapples with at some stage: whether or not to have another child.
This topic is discussed regularly on Trade Me's Parenting message board in threads entitled 'Tell me about going from two kids to three' and 'How did you know when your family is complete?'
Issues explored run the gamut from the purely practical such as financial ramifications, transportation issues and how to juggle a newborn's sleep patterns with a pre-schooler's kindergarten pick-ups to more deep and meaningful considerations.
Some people resist further children because of environmental concerns about the toll they will take on the planet's resources while some women speak of an intense longing to have another child, a strong intuitive sense that their family isn't complete yet.
Mum, dad and a couple of children remains a fairly standard family model.
Yet recently a trend towards three-child families has been noted. Some parenting publications and websites have been asking whether, as far as making babies is concerned, three is the new two?
It's safe to say that two-child families and three-child families are the most widely approved of. Although on the rise, single-child families continue to be frowned upon.
These parents are deemed selfish in their unwillingness or inability to provide their offspring with a sibling for companionship.
There are wild accusations that their lone child is more of an accessory to their shallow designer lives than fully fledged family member.
Even the harshest critics find it difficult to be too negative about families with two children. There's an undeniable symmetry with a child for each parent and a playmate for each child. There's also the distinct possibility of acquiring a child of each gender - which will surely please those keen on diversity in the family unit.
Since being a parent to children of both genders seems important to a significant proportion of people - including Victoria Beckham who has recently become the proud mother of a daughter after three sons - it's understandable that families with two sons or two daughters choose to try once more to see if it's third time lucky for the other elusive sex.
But plenty of families that have neatly checked off their boy and their girl with just two children are shunning such picture-postcard perfection and trying for a third child.
Predictably, this move is not without its critics. Why, some people say, would you have another when you already have one of each flavour?
Interestingly, just as parents of only children come in for criticism, those that choose to have large families routinely cop flak too. There's undisguised disapproval reserved for parents with more than say three or four children.
Strangers who encounter a modern day family of a size that hasn't been truly fashionable since The Waltons debuted on our television screens are often quick to judge such rampant breeding.
Last year I interviewed parents with six, eight and eleven children for a Canvas article about large families entitled And baby makes .... Comments routinely directed at these people include: 'How do you cope?', 'Are they all yours?', 'Don't you have a TV?' and - unbelievably - 'I hope you're not having any more.'
Ultimately, family size is a personal matter for each couple to resolve. Some of us seek to replicate the family we grew up in while others deliberately reject this structure in an attempt to improve on it when crafting our own family unit.
But whether parents opt to have one, two, three, four or oodles more children, the one thing we probably all agree on is that it's nobody's business but our own.