Overview
- The peer‑reviewed study published on Wednesday, October 14, 2026, exposed mice to low or high doses of cigarette‑smoke extract for 12 weeks and then measured tissue structure and gene activity in ovaries and testes.
- Female mice showed little loss of ovarian follicles but clear shifts in gene activity tied to cell division, metabolism and protein production that mirror patterns seen in ovarian ageing.
- Male mice given higher smoke doses developed measurable testicular changes, including enlargement of seminiferous tubules, plus altered gene expression linked to sperm production, immune responses and cell signalling.
- Study authors from the Universities of Nottingham and Sheffield present these tissue and gene changes as possible mechanisms that could help explain prior epidemiological links between smoking and poorer fertility but they stress that human studies are needed to confirm clinical impact.
- The results sit against a global infertility backdrop—about one in six people experience infertility—and could strengthen the case for more human research and for advising people trying to conceive to avoid smoking to reduce potential harm.