Britain's Biggest Family is expecting their 20th child, but how do you know what family size is right for you?

The Radford Family AKA Britain’s biggest family revealed yesterday that they were adding to their brood announcing the impending arrival of their 20^th child (Yep 20!)

Mum, Sue, 42 and her husband Noel, 45, who shot to fame on the TV show ‘16 Kids And Counting’ (and it’s subsequent 19 kids and counting update) announced the news on social media yesterday.

Sharing an image of a blackboard that contained the words “Boys – 10, girls – 9 and BABY makes 20. Arriving Sept 2017,” the family confirmed that the UK’s biggest family was about to get even bigger.

But while for many the very idea of 20 children will have them booking an appointment at the local family planning, big families are becoming more common in the UK.

In news that could mark the end of the traditional 2.4 children, Britain is now home to more families containing four or more children since the early 1970s. Experts put the increase down to an apparent trend for the very wealthy to have more babies, plus immigration. But while there has been an increase in the number of larger families in the UK, the average family size is shrinking.

New data has revealed that the average woman in Britain aged 45, now has 1.9 children. That compares with 2.35 for a 45-year old woman living in 1985. While in the past ten years, the number of one-child families has grown from 42 per cent to 47 per cent. At the same time the proportion of families with two and three children is on the wane.

The new figures suggest parents are becoming increasing divided about the family size to have, with only children and multiple births becoming more common at the expense of the more traditional two-child family.

But how do you know what size family is right for you? Society has quite a lot to say about the issue. With one-child families being criticised for being ‘selfish’ for condemning their only child to a lifetime of loneliness, while larger families field ‘selfish’ accusations for other reasons – not having enough time, money, beds for all their children.

And if we’re not running the gauntlet with public opinion about the amount of children to have, science is also giving us food for family size thought. The trouble is it’s all rather conflicting.

According to one study, assessing the happiness of British and German parents before and after the births of their children, having one or two children can boost your happiness, but pop out a third and, yeah, the effect is not so much.

That follows another study, published in the journal Social Science & Medicine, which suggests that having children is good for your health – as long as you stop at two.

The research studied more than 1.5 million men and women found that becoming a parent has a clear effect on the chances of developing conditions such as cancer and heart disease to becoming an alcoholic or dying in a car crash. But the link is not straightforward as it depends on the number of children you have.

Too few or none at all, and couples are at increased risk of dying from almost all of the conditions studied, perhaps because they lack the extra motivation to look after their health. But throw three, four or more small ones into the picture and they struggle to cope with the financial and emotional stress of bringing up a large family. The magic number according to this report is having two children, while worst off were those who were childless, or had only one child.

On the flipside, science has revealed some excellent benefits of one-child families. Studies reveal that only children report having closer ties with their parents. They are also slightly more risk-averse and less likely to go through a rebellious phase. Certain studies also reveal that in adult life, they are more likely to live close to their parents than those with siblings. (For some that’s likely debatable whether its a benefit or not, but there you go.)

It’s not all bad news for larger families either, with some research suggesting that children with lots of siblings actually perform better than those with fewer brothers and sisters.

A survey of 22,000 French school-leavers found that academic performance improved with additional siblings so long as one parent was “an educated professional”.

While some assume the larger the family the less time parents have to devote to reading to and helping with homework of individual children, parents of larger families believe that older siblings can often help act as teachers and the younger ones learn to work on their own.

There’s the cost implications of a big family to consider as well. Recent research from insurer Liverpool Victoria confirmed what most parents in Britain likely already suspected: the cost of raising a child in Britain is surging, rising by 62 per cent over the past 11 years to a whopping £227,000!

It’s hardly surprising therefore that some experts believe Britain is hurtling towards an accidental one-child policy. With many parents caught in some kind of baby-gap that sees them wanting a bigger family, but feeling unable to afford the extra childcare costs, bigger car, bigger house and on…

Advocates of larger families argue that it’s ok for siblings to share bedrooms, and in fact there may even be a health benefit to it. With bedroom-sharers boosting their immune systems, thanks to the fact they pick up everything from sleeping in such close proximity to other kids.

So whether you’re currently trying to switch off from the judgement of only having one child or you’re getting flack about wanting to keep procreating to Radford family proportions, take heart in the fact that family size is an equally divisive topic.

Chances are every child from a small family has probably envied friends with enough siblings to start their own football team, while many from a huge family might long for the type of one-on-one time their lesser-sibling-ed friends have with their parents.

The point is there are pros and cons to every family size, what’s important is you work out what’s right for you. Because the fact is unless everyone has 2.4 kids each, the arguments over family size will continue to rage.

Follow us on Instagram and Facebook for non-stop inspiration delivered fresh to your feed, every day. For Twitter updates, follow @YahooStyleUK.

Read more from Yahoo Style UK:

Is it time to stop teaching our kids about ‘Stranger Danger’ and instead tell them how to spot ‘Tricky People’?

Amal Clooney Has Already Rejected Two of George’s Baby Names