The failure of a couple to achieve pregnancy after one year of regular, unprotected intercourse is called .

The failure of a couple to achieve pregnancy after one year of regular, unprotected intercourse is called "infertility." Infertility can affect both men and women and may stem from various factors, including hormonal imbalances, structural issues in reproductive organs, age, lifestyle factors, and other medical conditions.

In women, factors such as ovulatory disorders, fallopian tube blockages, and endometriosis can contribute to infertility. In men, issues with sperm production, motility, or anatomy can play a significant role. If infertility is suspected, medical professionals typically recommend a thorough evaluation to identify potential causes, which may involve medical history assessments, physical exams, and specific tests for both partners.

It's important for couples experiencing infertility to seek professional advice, as various treatment options are available, including medication, assisted reproductive technologies, and lifestyle changes that can improve the chance of conception.