Concerns over China's shrinking working-age population convinced Beijing to repeal its controversial "one child" policy in 2015, much to the delight of the infant formula world.
The trouble is, Chinese couples have not been playing the game.
A year after the end of "one child", the birth rate surged by 8 per cent but promptly fell by 4 per cent in the following year.
Samuel Liu, secretary-general of China Nutrition and Health Food Association, said the rate fell by an estimated 3 per cent in 2018 and is projected to fall by 2 per cent in the current year, and by 4 per cent in each of the next two years.
At the same time, the number of women of child-bearing age between 25-45 is decreasing and the number of over 65s is increasing, he told an infant nutrition conference in Melbourne this month.
It seems that China, and much of Asia, is facing the demographic fact of life that has already become a feature of much of developed world - a declining working-age population.
Danone, the French food group and one of the world's biggest players in infant nutrition, this month reported a slowdown in its China sales, of 15 per cent in the first quarter.
The decline was put down to the falling birth rate, but it compared with a whopping 50 per cent lift in the first quarter of 2018.
So will the golden days of double-digit growth for infant formula soon reach their end?
David Mahon, the Beijing-based Kiwi businessman who advises companies wanting to set up shop there, said there's nothing in the birth rate to disturb New Zealand's $1 billion a year export infant formula trade to China.
A2 Milk says lift in dairy prices may impact in FY2020
"What matters for New Zealand is the middle class and upper-middle class," he said in an interview.
"They are the ones who will buy manuka honey and infant formula from New Zealand.
"So although it's true that the demographics of China paint a particular picture, the spreading of the middle class means that many are coming into the scope for those selling these expensive, sophisticated products, so I think we are in pretty good shape," he told the Herald after the conference.
Hamish Reid, who chairs the Australia and New Zealand Infant Nutrition Council, agreed there was little in China's declining birth rate to worry the world's infant formula makers, although the rate of growth was likely to fall more in line with China's GDP growth.
"China remains the biggest infant formula market in the world, and the dynamic there is more about the huge shift into the middle class rather than population growth.
"Half of the infant formula products sold globally are sold in China and that's driven by the increasing middle class," he said.
It was a similar story across southeast Asia, said Reid.
He said the 2008 melamine scandal, when adulterated formula claimed the lives of six babies and saw 50,000 require medical treatment, was a sea-change for the industry.
Paradoxically, foreign manufacturers of infant formula received a boost from the scandal.
"Foreign suppliers got a real kick. There was a radical shift from domestic of foreign suppliers because the Chinese market lost a lot of trust in the local industry."
More broadly, Reid says as the infant formula market starts to stabilise, he expects the sector's growth will match China's GDP growth of 5 to 10 per cent over the next few years.
"What you're not seeing is the significant growth in the category from when the one child category was relaxed, ironically.
"And I think that comes down to not how many kids you want, but how many kids can you afford, can you house, can you clothe, can you educate?"
That's backed up by a survey last year by FT Confidential, a research service, which found that more than half of married couples who were delaying having children cited the high cost of raising a child.
Much of the regulatory change, which has involved China streamlining its bureaucracy and processes while introducing a strict registration regime for manufacturers, are still ongoing because of the public outcry over the melamine incident.
"They've really put a lot of additional focus on their industry, and they've also looked to rebuild their industry and rebuild their domestic producers," said Reid.
"They've tried to support the consolidation of companies over there and have increased hygiene standards and the standard of products.
"And with that increasing support of their domestic industry, there have been new licensing requirements which foreign suppliers have been exposed to as well," he said.
Right now, many companies in Australia and New Zealand can't access the retail chain in China because they don't have approved products and that approval does take a long time, partly due to the restructure of the industry in China, Reid said.
"But what has happened is that the so called daigou, or grey market, channels that allow private individuals picking up product from particularly Australian supermarket shelves and exporting it to their networks in China, or the companies exporting direct and selling their products through online platforms in China.
"So that channel has remained open, which is critical to the viability of a lot of our member companies.
"I think some companies are particularly struggling because they don't have access to that retail chain in China.
"Those that do have access seem to be going relatively well, but each company has its own particular challenges whether it's a brand challenge or an innovation challenge, so it's an incredibly dynamic industry," he said.
The dynamics don't appear to be having much affect on the a2 Milk Company, the local sharemarket darling that's produced stellar returns for investors.
At a recent investor day in Australia, a2 said the Kantar market tracking of large Chinese cities showed its infant formula consumption value share increased to 6 per cent as of March, up from 5.4 per cent in December.
In China, its infant formula market share value rose from 5.4 per cent to 6 per cent, while in Australia and New Zealand that product's value share rose from 35.7 per cent to 36.8 per cent.
China distribution outlets rose by 1350 to a total 13,600 during the period, while US liquid milk distributors rose by 300 to 12,700 for the period, a2 Milk said
Group revenue accelerated a little in its third quarter, with sales for the nine months through March 31 being up 42 per cent.
However, it said second-half sales should be broadly in line with the first as it pumps money into marketing and building organisational capacity.
Overall, Reid says the Australia and New Zealand infant formula market is healthy, but he said there was some concern in the sector about rising trade friction between the US and China.
"Anything that's going on geopolitically that impacts on their ability to trade with China is very concerning," he said.
"It flows through to the concern about unemployment for the people who work in those companies, with China being such a massive market for them."
• Jamie Gray attended the Infant Nutrition Conference in Melbourne, courtesy of the New Zealand and Infant Nutrition Council.