Is HbA1c useful for fertility?

HbA1c reflects average blood glucose over 2–3 months. Elevated HbA1c (≥5.7 %) indicates poor glycemic control, which is linked to reduced fertility in both women (e.g., anovulation in PCOS) and men (e.g., impaired sperm quality). Observational studies associate higher HbA1c with increased miscarriage risk and pregnancy complications. However, HbA1c is not a direct fertility test—it provides metabolic context but cannot diagnose infertility. Evidence for the fertility link is human-moderate (observational). Caveats: HbA1c can be falsely low in anemia or hemoglobinopathies, and falsely high in kidney disease. A normal HbA1c does not rule out fertility issues, and an elevated value alone does not confirm them. It is useful as part of a broader workup (e.g., with hormone panels, semen analysis). Safety: no direct risk from the test, but misinterpretation may lead to false reassurance or unnecessary interventions. Always discuss results with a healthcare provider.