Daijiworld Media Network - Copenhagen

Copenhagen, Jun 18: Adults born to parents who experienced difficulty conceiving may face a higher risk of infertility later in life, according to a Danish cohort study that highlights a possible intergenerational link in reproductive health.

The research found that both prolonged time to pregnancy (TTP) among parents and a maternal history of infertility were associated with a greater likelihood of infertility in their children during adulthood.

Infertility, defined by the World Health Organization (WHO) as the inability to achieve pregnancy after 12 months or more of regular unprotected intercourse, affects around one in six people of reproductive age globally.

Researchers analysed data from 11,144 adults born to women enrolled in the Danish Health Habits for Two cohort between 1984 and 1987. Parental time to pregnancy was grouped into three categories — one to six months, seven to 12 months, and more than 12 months.

The study found that daughters whose parents took seven to 12 months to conceive had a 43 per cent higher risk of infertility, while those whose parents took more than a year to conceive faced a 41 per cent higher risk. A clear trend suggested that infertility risk increased with longer parental conception times.

Among sons, the association was less pronounced but still indicated a modest increase in infertility risk when parents took longer than 12 months to conceive.

Researchers also observed that a maternal history of infertility significantly increased the likelihood of infertility in offspring. Sons born to mothers with a history of infertility faced an 81 per cent higher risk, while daughters had a 49 per cent increased risk.

The findings suggest that reduced fertility may, to some extent, be transmitted across generations. However, researchers cautioned that the study was observational and does not establish a direct cause-and-effect relationship.

They also noted that the study assessed infertility history only among mothers and did not specifically evaluate paternal infertility, making it difficult to determine the relative contribution of each parent.

The researchers called for further studies to explore the biological, genetic and environmental factors that may explain how fertility challenges are passed from one generation to the next.