By Lisa Rapaport

Adults who were underweight babies or early arrivals may be less likely to have romantic or sexual relations or become parents than their counterparts who were full-term infants, a research review suggests.

Compared to adults who were full-term babies, those who were premature or low birthweight infants were 57% less likely to have sexual intercourse, 28% less likely to have romantic relationships and 23% less likely to become parents, the analysis of data on more than 4 million people found.

“What we know from previous studies is that preterm-born children are usually timid, socially withdrawn and low in risk-taking and fun seeking,” said Marina Mendonca, lead author of the study and a researcher at the University of Warwick in the UK.

“These characteristics might make it harder for individuals born preterm to form social relationships in adulthood, such as finding a partner,” Mendonca said by email. “But when adults who were born preterm had friends or a partner, the quality of these relationships was as good as those born full-term.”

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 and tiny babies later in life, researchers examined data from 21 previously published studies comparing adult social outcomes for these vulnerable infants to their full-term counterparts.

The negative impact of being premature or underweight was similar for men and women and for adults at all ages.

However, the negative effects were more pronounced for the earliest arrivals and the tiniest infants.

Extremely preterm babies who arrived before 28 weeks’ gestation were 67% less likely to have romantic partners and 69% less likely to become parents in adulthood than full-term infants.

Very preterm babies who arrived at 28 to 31 weeks’ gestation were 33% less likely to have romantic partners and 21% less likely to become parents than full-term infants.

In contrast, moderate- to late-preterm babies who arrived at 32 to 36 weeks’ gestation were only 21% less likely to have romantic relationships or become parents compared with full-term infants.

The researchers were not able to examine how disability or health problems common among preemies and underweight babies might have impacted adult relationships, the study team writes in JAMA Network Open.

Even so, the results suggest that it’s never too soon for parents of preemies and underweight babies to start helping them build social skills that may be challenging for them as they grow up, Mendonca said.

“Those caring for preterm children, including parents, health professionals and teachers, should be more aware of the potential important role of social development and social integration for preterm children,” Mendonca said.

“As preterm children tend to be more timid and shy, supporting them making friends and being integrated in their peer group may help them to later find romantic partners, have sexual relationships and to become parents, all of which enhances wellbeing.”

SOURCE: and JAMA Network Open, online July 12, 2019.