Twenty-somethings who were born prematurely are less likely to move in with a lover or have sex than their peers born at full term, Finnish researchers find.

These young adults are also less likely to consider themselves sexy. And, more of them have never moved out of their childhood home.

"Previous studies have found that individuals born preterm might be more cautious and less risk-taking than those born at full term, which might also be reflected in our findings of lower likelihood of romantic relations," said lead study author Dr. Tuija Mannisto, a researcher and fellow in clinical chemistry with the National Institute for Health and Welfare and the Northern Finland Laboratory Centre Nordlab in Oulu, Finland, in email to Reuters Health.

Pregnancy normally lasts about 40 weeks, and babies born after 37 weeks are considered full term. In the weeks immediately after birth, preemies often have difficulty breathing and digesting food. Some premature infants also encounter longer term challenges such as impaired vision, hearing, and cognitive skills as well as social and behavioral problems.

To examine the romantic prospects of preemies later in life, the researchers reviewed questionnaires completed by people born in Finland between 1985 and 1989. The average age of the study participants was about 23 years.

Overall, 149 participants had been born early preterm (less than 34 weeks gestation), 248 were born late preterm (between 34 and 37 weeks), and 356 were born at full term.

Compared to individuals who were full-term, those born late preterm were 20 percent less likely to have ever lived with a romantic partner and 24 percent less likely to have ever had sex.

The findings were similar for people born early term, though after taking other variables into account, the difference wasn't statistically significant.

The researchers also saw that fewer of those born early had ever moved out of their parents’ house, but that difference too was no longer statistically significant after adjusting for other factors.

Asked to rate their sexual attractiveness on a scale of zero to 10, preemies on average gave themselves a lower score. With 10 being the sexiest, full-term participants rated themselves a 6.9 on average, compared with 6.5 for late preterm individuals and 6.2 for early preterm.

The findings show that social outcomes related to preterm birth aren't limited to those with the most severe prematurity, and, in fact, extend to many people born even just a week a two early, the researchers note in their report in the journal Pediatrics.

While the results may have some relevance outside of Finland, babies born there have many advantages not as widely available elsewhere. For example, Finland has few children living in poverty and offers generous parental leave and allowances for childcare, all factors that can contribute to better outcomes for preterm infants.

"At the end of the day, one of the best predictors of outcomes is maternal income and education and socioeconomic status," said Dr. Kristi Watterberg, a neonatologist at the University of New Mexico who wasn't involved in the study.

A preemie born to a mother living in poverty in the U.S. who works multiple jobs and has no access to affordable child care is probably going to fare worse than a baby born with more advantages in Finland, she told Reuters Health.

Still, there are several things parents can do to improve prospects for their preemie, said Watterberg, who also chairs the American Academy of Pediatrics Committee on Fetus and Newborn.

In the weeks immediately after birth, preemies can benefit from skin to skin contact, breastfeeding, and being touched in a gentle, soothing way that doesn't overstimulate them, she said. Cooing, and mimicking their sounds and actions also helps these babies engage with the world around them and build social skills.

Watterberg also cautioned that the Finnish study findings may not necessarily mean that preemies grow up to be unhappy adults.

"What we have seen with kids is that babies who are born preterm tend to be more risk averse and shy and more fearful," Watterberg said. "But on the other hand, we have seen that these kids tend to grow up and develop a good life, a life the kids and their parents are happy with."