Boys or girls, do Kiwi parents care?
Fletcher, Spencer, Sebastien and Casper.
Christchurch parents Shar and Ashley Sutherland Todd say they love having four lively sons.
The couple have a bigger family than the national average, but not because they wanted a gender balance.
"A lot of people thought we were trying for a girl, but we definitely weren't," Shar Sutherland Todd said.
"I come from a big family, but I don't think ours is big. It's a lot of fun with the boys and we love having a lot of people around."
How much does the size of Kiwi families depend on whether parents want both boys and girls?
If a couple has two girls, or two boys, are they more likely to have a third child to try and achieve gender balance? Which gender are they more likely to be trying for? Or do they just want a bigger family, regardless of gender, like the Sutherland Todds?
Statistics New Zealand set out to answer those questions by studying the nation's live birth records from 2007 to 2015.
With low fertility rates meaning the nation cannot maintain its population without migration, people's motivations for having bigger families could be important, the department said. On average, each woman had 1.8 children, a figure which included women with no children.
The research, just released, found 45 per cent of families having baby number three already had a girl and a boy, while 55 per cent had just girls or just boys. So although many births are unplanned, the number revealed parents with a boy and a girl were more likely to stop at two.
So how do the numbers look when it comes to a fourth child?
The researchers calculated that a family with three children of the same sex was about 4 percent more likely to have a fourth child than one that already included at least one son and one daughter.
The researchers concluded attempts at gender balance did have an effect on the county's fertility levels and boosted population, partly as New Zealand has no legal method of gender selection.
Were the couples trying to balance the genders more likely to be trying for a boy or a girl?
The results revealed more families with two boys had a third child than families with two girls. But Statistics NZ concluded this did not mean more parents felt the need for a girl.
The difference was explained by the gender imbalance at birth – with 106 boys born for every 100 girls in New Zealand, there are slightly more families with boys than girls to start with.
The researchers noted that while in some under-developed countries boys are preferred for social security or their strength for physical work, and some countries favour girls as they are considered to provide better care and emotional support, most first-world nations show no preference and couples have children for personal reasons such as family ties, affection and fun.
Shar Sutherland Todd said one benefit of having four children was that it boosted her and Ashley's chances of becoming grandparents. Their sons are aged between seven and 20.
"It's going to be really nice knowing we should always have family in our lives, including, hopefully, grandchildren one day."