Adults who were born prematurely or with low birth weight are less likely to have romantic partnerships or sexual intercourse or to become parents, according to a new study published Friday.

The meta-analysis, carried out by researchers at the University of Warwick and published in the journal JAMA Network Open, analyzed the results in 21 studies involving social outcomes in 4.4 million adults who were born preterm or with low birth weight.

The results revealed that adults born preterm (a birth that occurs before the 37th week of pregnancy) or with low birth weight were 28% less likely to have romantic relationships and 22% less likely to become parents. In addition, adults born preterm were 2.3 times less likely to have a sexual relationships than those who were born full-term.

“These findings suggest that adults born preterm or with low birth weight are less likely to experience a romantic partnership, sexual intercourse, or to become parents. However, preterm birth or low birth weight does not seem to impair the quality of relationships with partners and friends. Lack of sexual or partner relationships might increase the risk of decreased well-being and poorer physical and mental health,” the study concludes.

The study also found that lack of sexual activity and “romantic partner support” was associated with poorer mental and physical health, as well as lower reported levels of happiness.

The researchers believe that adults who were born preterm are less likely to form romantic relationships and become parents due to “poorer social interactions” during childhood.

"The finding that adults who were born preterm are less likely to have a partner, to have sex and become parents does not appear to be explained by a higher rate of disability,” first author of the study Dr. Marina Goulart de Mendonca told Sky News.

"Rather, preterm-born children have been previously found to have poorer social interactions in childhood that make it harder for them to master social transitions such as finding a partner, which in turn is proven to boost your wellbeing,” she added.

Dr. Chiara Nosarti, a reader in neurodevelopment and mental health and the head of psychology and outcome studies at the Centre for the Developing Brain, King’s College London, agreed that people born preterm face social adjustment issues.

"Several studies have investigated preterm individuals' social outcomes at different stages of life, and the general consensus across studies is that social adjustment difficulties following preterm birth emerge in childhood and remain throughout the lifetime,” she noted, Sky News reported.

However, the analysis is not without limitations, due to the “considerable variations” of how romantic relationships were evaluated across all the studies.

“For example, quality of romantic relationships included studies reporting on satisfaction with partner and intimacy, and social support included studies reporting on emotional closeness with friends to self-reported quality of social network,” the study notes, also recommending that additional individual studies be carried out with similar measures to ensure homogeneity.