Preterm Birth Impacts Adult Relationships, Fertility

Preterm birth has lasting effects into adulthood, with very preterm individuals struggling to form romantic relationships and having fewer children, according to the Bavarian Longitudinal Study. Published in JAMA Network Open, the study, led by Miranda Kit-Yi Wong, MSocSc, from the Department of Psychology, University of Warwick, Coventry, United Kingdom, tracked very preterm infants born since 1985, now aged 34-35 years, and compared them with full-term individuals.

The researchers analyzed 414 participants, including 212 very preterm (< 32 weeks’ gestation) or very low–birth weight (VLBW) individuals (< 1500 g) and 202 full-term individuals. The results showed that by the age of 34-35 years, 56.4% of full-term individuals had children compared with only 35.8% of preterm individuals.

Previous cross-sectional studies have suggested a link between a history of preterm birth and fertility.

“The Bavarian Longitudinal Study, however, has been ongoing for nearly 40 years. The cohort of newborns included back then is now 34-35 years old and has been evaluated 10 times,” said Peter Bartmann, MD, PhD, co–project leader and professor at the University Hospital Bonn in Bonn, Germany.

For Bartmann, it is important to emphasize that the project only concerns those born very early and very small and by no means all premature babies. “This is only a small group of those affected, about 1%-1.5% of births,” he said.

Speaking with Medscape’s German edition, Dominique Singer, MD, PhD, professor and head of the Division of Neonatology and Pediatric Critical Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, who was not involved in the study, emphasized, “This is an internationally recognized phenomenon, but it has previously been described only cursorily and not longitudinally and is being examined in a focused manner for the first time. Such differences compared to full-term individuals can significantly impair the quality of life in the long term, especially when an unfulfilled desire for children leads to loneliness later in life.”

Long-Term Quality of Life

Key factors such as gender and socioeconomic status influenced outcomes, but the link between preterm birth and fertility persisted. However, this association was no longer significant after adjusting for partnership status.

“Individuals with a history of preterm birth find it harder to establish a partnership, which in turn reduces the likelihood of having children,” Bartmann explained.

Preterm individuals who formed partnerships had children at rates comparable with those of full-term individuals.

Personality and Social Challenges

Why do preterm individuals struggle to form partnerships? “Studies show that this group develops a different personality structure,” Bartmann noted. “They are more introverted, take fewer risks, face bullying in school, have fewer friends, and struggle to form social connections.”

Family dynamics also play a significant role. “In some families, preterm birth is rarely mentioned, while in others, it is emphasized that the children are ‘special’ or face greater challenges,” said Singer.

There is also evidence that psychological factors, not just physical differences, play a role. Interviews with adults born prematurely suggest that families handling premature births can shape a child’s personality, as noted by Singer.

Delayed Fertility Differences

The study clarified why earlier research has yielded conflicting results. Fertility differences between preterm and full-term individuals only became apparent in their late 20s and early 30s.

“There seems to be a dichotomy here between young adults for whom a history of preterm birth no longer matters — those who start families early — and those who continue to struggle into middle adulthood,” Singer said.

Growing Preterm Population

With advances in neonatal care, survival rates for very preterm infants have improved significantly. Globally, approximately 10% of births are preterm, with 10% of these being VLBW or born at less than 30 weeks’ gestation.

Singer noted, “Even for preterm infants born at 23-24 weeks — the threshold of viability —current survival rates range from 60%-80%, although a quarter to a third experience immediate neurological complications.”

“This is why it is important to be aware of the long-term and far-reaching consequences of preterm birth,” Bartmann emphasized. “Support for preterm infants currently focuses on the early years of life. Once they start school, they are left to fend for themselves.”

“This is why it is important to be aware of the long-term and far-reaching consequences of preterm birth,” Bartmann concluded.

The Bavarian Development Study suggests that very premature or LBW babies may benefit from long-term monitoring and tailored support. Researchers have recommended training educators to help prevent bullying. To support this, Singer, in collaboration with the Federal Association “The Premature Child” e.V., has created an information brochure for general practitioners, with one for teachers in progress.

This story was translated from Medscape’s German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.