Most women still consume harmful substances like alcohol and caffeine while trying for a baby, suggesting low awareness of the risks, new research has found.

Research published today in BMC Pregnancy & Childbirth led by King's College London and UK pregnancy charity Tommy's studied 131,182 women who used Tommy's Planning for Pregnancy tool, which asks questions about maternal health to give tailored advice on lifestyle changes that can reduce pregnancy risks. The research team found troubling trends in women's lifestyles while trying for a baby, particularly among the under-25s and those with a BMI below 18.5.

One in five women planned a pregnancy smoked cigarettes, and 3.7% said they used recreational drugs. Younger or underweight women were more likely to take these risks, with 31% smoking and 5% taking drugs even while actively trying for a baby. These women were also the least likely to be taking proactive steps like vitamin supplements to improve their health, so the study authors are calling for targeted national efforts to engage and support these groups.

It was found that 53% of women in the study ate their five-a-day, and 43% exercised for the recommended 150 minutes a week. Another concerning finding was that most (60%) women with a long-term health condition or history of pregnancy complications hadn't spoken to a doctor about their plans for a baby, which could open the door to crucial preconception care.

The team observed some short-term shifts toward healthier behaviors but warned these may not be enough to have significant benefits—and for some behaviors, the opposite was true. For example, 20% of those who'd stopped using contraception were smoking, yet 24% smoked if they'd been trying to conceive for a year or more. Researchers also highlighted that women who drank alcohol were more likely to consume caffeine, suggesting low awareness of how cutting down on these things can aid pregnancy.

"Every parent wants to give their children the best start in life, but our study suggests it's not well known in the UK that people can take steps before they even start trying to increase their chances of having a safe pregnancy and a healthy baby. Despite lots of evidence that folic acid supplements improve pregnancy health, few people we studied were taking them when trying for a baby—and research from the turn of the century found similar trends, so it's worrying that awareness and behaviors haven't really improved. The road to parenthood isn't always straightforward so it's vital to let people know how they can prepare themselves, as well as having support services available for anyone who needs help to give up risky but addictive behaviors like smoking or drug use," says author Dr. Angela Flynn, nutritional sciences lecturer from the School of Life Course Sciences.

Study findings will contribute to an 'annual report card' recommended by the UK Preconception Partnership to measure progress on targets for improving the nation's health, once specific interventions to help people to prepare for pregnancy are added into existing public health strategies tackling related issues like smoking and obesity.

Co-author Dr. Sara White, from the department of Women & Children's Health, explained: "Our study highlights the importance of targeted support for women planning a pregnancy. This data can be a benchmark to inform the national public health strategy, as proposed by the UK Preconception Partnership; they currently have access to NHS patient data from early pregnancy appointments, but here we have real world insight from people still in the planning stages. We've also got a unique window onto these women's behavior, as they may well be more open when anonymously using the Tommy's tool than if we asked face-to-face in a clinic setting."

Drs. White and Flynn are now leading another study to see if people identified by the Tommy's tool as facing lifestyle-related pregnancy risks can be supported to change their behavior and improve their health through specialist coaching.

Dr. Edward Morris, president of the Royal College of Obstetricians and Gynecologists, said: "We welcome the call for a research strategy looking into women's lifestyles while trying for a baby. There is a lack of information about the actions that women can take when planning a pregnancy in order to increase fertility, increase the chance of having an uncomplicated pregnancy, and help achieve the best outcome for mother and baby. We have called for improved access to information and support on pre-conception health in our Women's Health Strategy, as the promotion of healthy behaviors will not only improve the health of the individual, but will positively impact future generations."