The factor that is not a risk factor for SIDS is routine childhood vaccinations (immunizations). Vaccines have not been shown to increase SIDS risk and are actually recommended for overall infant health and may be associated with a lower risk of sudden infant death.

Quick Scoop: Real SIDS Risk Factors

Evidence‑based risk factors for SIDS include:

  • Sleeping on the stomach or side instead of the back.
  • Sleeping on soft surfaces , with loose bedding, pillows, or many blankets.
  • Bed‑sharing with adults or other children, especially on sofas or armchairs.
  • Prenatal and postnatal tobacco smoke exposure (mother smoking in pregnancy, or anyone smoking around the baby).
  • Prematurity or low birth weight.
  • Young maternal age (younger than 20), limited or no prenatal care.
  • Overheating, head covering, or very warm sleep environments.
  • Family history of SIDS in a sibling.

By contrast, these are protective rather than risky:

  • Back‑sleeping (on the back for every sleep).
  • Breastfeeding.
  • Using a pacifier at sleep time (once breastfeeding is established).
  • Room‑sharing without bed‑sharing (baby in their own crib or bassinet in the parents’ room).
  • Staying up to date on vaccinations.

In many test or quiz questions, the correct answer to “Which of the following is not a risk factor for SIDS?” is “immunizations/vaccinations” or another clearly protective factor like “breastfeeding,” depending on the answer choices given.

If you share the specific options you’re choosing from, I can tell you exactly which one is the “not a risk factor” choice.