How early-life adversity relates to reproductive health: fertility and pregnancy outcomes in the Norwegian HUNT Study

OBJECTIVE: To provide a more comprehensive understanding of how childhood adversity influences reproductive trajectories, this study assessed associations between childhood adversities and parity, infertility, and adverse pregnancy outcomes in a population-based cohort. DESIGN: A cross-sectional study was conducted by linking the third (2006-2008) and fourth (2017-2019) surveys of the Trøndelag Health Study to the Medical Birth Registry of Norway. SUBJECTS: The study population included female participants from the third and/or fourth survey of the Trøndelag Health Study who were born in ≥1950. EXPOSURE: Childhood adversities were self-reported across six questionnaire items capturing experiences of a difficult childhood environment. MAIN OUTCOME MEASURES: Outcomes included parity, self-reported history of infertility, and four adverse pregnancy outcomes: gestational diabetes, hypertensive disorders of pregnancy, preterm birth, and small for gestational age. RESULTS: A total of 27,259, 22,071, and 23,083 women were included in our analyses of parity, infertility, and adverse pregnancy outcomes, respectively. Childhood adversities were associated with distinct parity patterns, including increased odds of nulliparity, parity of one, and parity of four or more births. Women reporting a difficult childhood had higher odds of infertility (odds ratio 1.35, 95% confidence interval 1.17 to 1.55). Exposure to childhood adversities was associated with higher odds of small for gestational age and preterm birth. CONCLUSION: These findings indicate that childhood adversities may have long-term consequences for reproductive health, including both fertility and pregnancy outcomes. The results underscore the need to consider the entire maternal life course experience in public reproductive health strategies and obstetric practice.