Maternity leave does not automatically reduce your State Pension, but it depends on your National Insurance record during the leave. While you receive earnings, Statutory Maternity Pay or Maternity Allowance, National Insurance contributions or credits may help protect your qualifying years, depending on your circumstances. If you claim Child Benefit for a child under 12, you may normally receive Class 3 National Insurance credits, even if you do not pay contributions. Check your State Pension forecast and National Insurance record on GOV.UK, and consider contacting HMRC if anything appears missing.