Dr Jonathan Sher said those who smoke, take drugs or are obese should be asked to consider delaying pregnancy.
In a report for NHS Greater Glasgow and Clyde, he said the change was needed to ensure more babies are born into healthy circumstances.
Any intervention was not about "shaming and blaming" women but empowering prospective parents, the research said.
It is based on an initiative by the Oregon Foundation for Reproductive Health in the United States.
Dr Sher, who is also Scotland director of the Wave Trust, said all prospective parents wanted a safe pregnancy, a healthy baby and a rewarding parenthood.
He told BBC Radio's Good Morning Scotland programme: "There are two ways of not having a risky pregnancy and not having an unhealthy baby. One is to do everything you can on the positive side to ensure good outcomes but the other is to not get pregnant."
He said the report was fundamentally about what the government, families and communities could do to help the next generation of parents and children be as healthy as possible.
That meant sometimes it was a "good idea" to delay pregnancy for those who had significant health of behaviour problems until they had the help they needed.
"It's not a matter of somebody making a judgement about others, there's absolutely nothing in this report that's about naming, shaming and blaming women or prospective parents," he said.
"It is about helping them to become better informed and empowered to make the best decisions about their own reproductive lives and their own future plans as parents. It is helping them to get what they already want, not imposing upon them."
NHS Greater Glasgow and Clyde said the pregnancy statistics highlighted in the report mirrored Glasgow and Scotland's poor health profile and reinforced the need to tackle "stubborn issues" like poverty, healthy behaviour and diet.
A spokeswoman added: "The report highlights the importance of this issue. At present there is no international evidence of effective interventions that improve pre-conception health of both future parents, the pregnancy outcomes and the health of the child.
"There is clearly a need to work with the wider international networks to create an evidence base for effective interventions."
Health professionals should ask men and women every year if they are planning a pregnancy, a health expert has said.