''But it's actually a precipitous cliff from about age 34,'' reproductive biologist John Aitken says as he spoons barramundi topped with caviar into his mouth.

It's a startling statement. I imagine, as I near 30, my eggs ending up like the caviar on his plate; shrivelled and unfertilised. ''I'll keep that in mind,'' I mumble.

My reaction must be nothing new for the scientist, who has spent the past 40 years uncovering the intricacies of the union between sperm and egg. ''My daughter-in-law runs when she sees me coming,'' he admits. ''She thinks we're going to have the egg debate.''

It's not just a female issue. Men's fertility declines, too, he assures me. But it starts about age 40 and is more a gentle slope than a precipitous cliff.

Sperm, more than eggs, have been the focus of Aitken's long and distinguished career, which has seen him awarded many scientific prizes and positions, including NSW Scientist of the Year in November.

While working at the University of Edinburgh in the late 1980s, he uncovered a major cause of male infertility; molecules generated by smoking, obesity and age, known as free radicals, could attack sperm DNA, he found.

The British-born biologist's discovery has helped thousands of men father children, and it would be hard to find an Australian man with a fertility problem today not taking antioxidants - the treatment against free-radical generation.

Right now, however, Aitken is less concerned with deliberate conception and more focused on accidental pregnancy. ''In NSW, twice as many foetuses are aborted as people die of cancer,'' he says.

There were about 29,000 Medicare-supported terminations in 2009 in NSW/ACT.

''That says we don't have adequate methods of controlling fertility,'' Aitken says. It is a problem he has spent the past few decades attempting to solve. His work with the World Health Organisation in the mid-1970s resulted in the world's first abortion pill, RU486.

And his group at the University of Newcastle patented a world-first female contraceptive three years ago that prevents both pregnancy and the passing of sexually transmitted infections. If the chemical succeeds in both animal and human trials, it will be the first major advance in contraceptives since the pill was introduced in the 1960s.

Every year the National Health and Medical Research Council spends more than $200 million on cancer research but not a cent on fertility control, Aitken says.

''When you think of all the miracles of modern medicine that have transformed healthcare in the last half century, here is something that impacts all our lives and it has been totally neglected.''

The softly spoken scientist plans to use the publicity of his latest award to raise awareness of the country's rising abortion rate, and our need for better contraceptives.

For someone whose career has focused on preventing unwanted surprises, Aitken's introduction to science was something of an accident.

Born into a family of real estate agents in Devon, Aitken quit school at 16 to sell houses to the semi-rural folk of Barnstaple. He lasted six months. ''Watching the clock tick around to five o'clock every day was driving me mad,'' he says.

Aitken re-enrolled at his former school to study art, English and geography. When the headmaster said those classes were full, Aitken was encouraged to study chemistry, botany and zoology, or ''plants and animals and things'', as that headmaster put it.

''In that nanosecond, when I was 16 years old, my whole life changed,'' Aitken says. ''I often wonder what life would have been like if I had stayed a real estate agent.''

But he was not a fully committed scientist yet. While he studied zoology at the University of London, his true passion was music.

''I played guitar most of the time so I didn't have the greatest university career,'' says Aitken, who shared a flat with 12 people, ran the university's folk music club and, like many of his generation, found kinship in Bob Dylan lyrics. ''His first album completely changed my life.''

Music at that point consisted of Frank Sinatra and the Nelson Riddle Orchestra, he says.

''Here was somebody singing about the role of government, the need for peace, he'd write songs about people having nervous breakdowns. Nobody had written songs about those sorts of things before,'' says Aitken, who, 40 years later, rises every day at 6am for a solo, pre-work jam session on his guitar.

''What I love about playing a musical instrument is that it completely disconnects your brain to some other place.''

It is easy to see why Aitken feels at home in Newcastle's artistic quarter.

We are dining at The Bistro in Cooks Hill, a suburb that houses the country's highest proportion of artists per capita. Aitken and his wife live around the corner.

We skip entrees and both order the steamed barramundi with champagne veloute, asparagus, basil, cucumber, kipfler potatoes and those darn fish eggs. Aitken splurges on a light beer.

When our meal arrives he notes the ''interesting'' cream-coloured froth - the champagne veloute - that garnishes the fish.

Aitken, who has worked and studied at some of the world's most prestigious research institutions including Cambridge and the World Health Organisation, says there is no place he would rather be than Newcastle.

The people are honest and kind, and the university comes without the pretensions of its more lofty counterparts, he says. But it was none of these features that first drew the scientist to the NSW coast.

After 20 years leading a research group in Edinburgh, he received a call from the University of Newcastle offering him a job. ''I thought they meant Newcastle upon Tyne, which is 40 miles down the road [from Edinburgh], so I said no thank you.''

A friend convinced him to visit the university with the added incentive of attending a West Indies versus Australia cricket match at the SCG.

''So I came over to watch cricket and never went back.''

More than 15 years later, Aitken co-leads a group of 150 researchers at the university's priority research centre in reproductive science.

As well creating the spermicide that kills sexually transmitted infections, the team is focused on the contraceptive holy grail: a male pill.

It is a difficult task; contraceptives for women must stop the ovulation of one egg a month. Men produce 1000 spermatazoa a second.

But Aitken gets most excited when he talks about the latest invention he is working on - a non-surgical method to sterilise animals such as cats and dogs.

The waitress overhears our conversation and chuckles as she piles our coffee cups onto her tray. I look around and think it lucky we have been the restaurant's only patrons for the past hour. ''When I'm with other professional people and we're in a room discussing sperm and semen, I notice that everyone else stops talking,'' says Aitken, who still marvels at the basic mechanics of biology that make all life possible.

''It still amazes me that within an egg - a tiny thing you can't see - is all the information you need to build a mammal.''

But Aitken is aware of the larger reproductive problem that lies beyond the microscope - Earth's unsustainable population growth.

It was while completing a PhD at Cambridge in the early 1970s, when the world's population tipped 4 billion, that Aitken first became concerned with the birth rate.

When the British government set up two reproductive research institutes at the University of Edinburgh to investigate ways of controlling fertility, Aitken moved north with a sense of purpose.

''For the first time in my life I tried to make a connection between the research we were doing at the bench and the broader issues of human reproduction,'' he says.

Soon after, Aitken was approached by the World Health Organisation to establish a research program that focused on contraceptives to be taken after intercourse. He spent a year travelling the world consulting and funding the world's best reproductive researchers.

Out of the program came RU486, more commonly known as the abortion pill. It blocks the hormone progesterone, which prevents a fertilised embryo implanting in the uterus.

Despite the controversy that surrounded the drug - it was banned in Australia until 2006 - Aitken believes it is an ideal contraceptive that should be promoted more in Australia to reduce the rate of abortions.

The highest proportion of women who terminate a pregnancy are at either end of their reproductive life - in their teens or above 40.

''Taking RU486 for a couple of days is infinitely better than going to hospital and having a first trimester abortion,'' Aitken says.

Life and Times

1947: Born Bath, England.

1963: Quit Barnstaple Boys Grammar School aged 16.

1963: Re-enrolled at school after six months as a real estate agent.

1966-69: Studied zoology at the University of London.

1970-74: Started PhD at the University of Cambridge.

1975-76: Moved to Geneva to work for the World Health Organisation.

1977: Started reproductive biology laboratory at the University of Edinburgh.

1986-87: Awarded Walpole Prize for fertility research.

1995: Elected to the Royal Society of Edinburgh.

1998: Moved to Newcastle, Australia.

2011: Elected fellow of the Australian Academy of Science.

2012: Named NSW Scientist of the Year.