(Reuters Health) - Most university students may plan to have children in the future, but they also probably overestimate how much time they have before their fertility starts to wane, an Australian study suggests.

In a survey of more than 1,200 university students, more than 90 percent said they saw kids in their future, but less than half could correctly identify the age when a woman’s fertility declines and even fewer knew when a man’s fertility drops off, the study authors report in the journal Human Fertility.

“Our study shows that young men and women overwhelmingly want to become parents one day. However, there are many other things they want to achieve in life,” said lead author Dr. Eugenie Prior of the Victorian Assisted Reproductive Treatment Authority in Melbourne.

“They want to advance in their career, be financially stable, have traveled, and be in a stable relationship before they have children, which does not leave a lot of time before their fertility starts to decline,” she told Reuters Health by email.

Several factors affect fertility and reproduction, including parental age, smoking and obesity. Among those, a woman’s age is often the most important factor in determining the chance of conception, the study authors note. Female fertility can begin declining between ages 30 and 34, and speeds up at ages 35-39, and male fertility can begin to decline after 40, and drops markedly at ages 45-49.

Morever, assisted reproductive techniques (ART) are not a guaranteed means of turning back the clock. Based on current evidence, the chance of a successful pregnancy after one IVF cycle in a woman over age 40 are roughly 5 percent, compared with 21 percent at ages 30-34, the study team points out.

“It’s so important that young people start talking about their goals and aspirations for parenthood, but also that they have the necessary knowledge about the limits of their fertility so they can make an informed decision about when they start a family,” Prior said. “This will give them the best chance for achieving their goals for parenthood.”

Prior and colleagues surveyed 1,215 University of Melbourne students about their intentions and expectations for future parenthood, knowledge about fertility, and preferred sources of fertility information.

Of the students who said they wanted children, about 75 percent wanted two or more and about half wanted to have their last child at age 35 or older.

Some 75 percent underestimated the impact of female age on fertility, and 95 percent underestimated the impact of male age.

“In developed countries, the median age of women at first childbirth has been rising steadily over the past three decades,” said Celia Chan of the University of Hong Kong, who wasn’t involved in the study.

“Family planning has long emphasized pregnancy prevention such as safer sex, contraception and prevention of sexually transmitted infections,” she said by email. “It is also essential to include education on fertility protection.”

Although some schools incorporate these messages in high school, the future can seem too far off, said Andrew Shelling of the University of Auckland in New Zealand, who also wasn’t involved in the study.

“This is a difficult message to make clear when the reality of delaying fertility is really years ahead,” he said in an email. “Perhaps increasing general knowledge is a possible way forward.”

When asked their preferred sources of information about fertility, the Australian students said they most often consulted the internet and family doctors. Roughly 90 percent also said they’d feel comfortable if their doctor raised the topic of fertility with them, prompting the study authors to recommend that general practitioners incorporate these conversations into routine patient visits.

“I think it’s important to note that young men are as keen to have children as young women,” said Sara Holton of Monash University in Melbourne, who wasn’t involved in the study.

“Fertility and childbearing are often viewed as only relevant to women or as ‘women’s issues,’ so it is good that men have been included,” she said by email. The next steps should “assist people to make informed decisions about childbearing.”

SOURCE: bit.ly/2vwk18a Human Fertility, online July 30, 2018.