Since you are in your fourth month (second trimester), this is the ideal time to receive your tetanus vaccination. If your first child was born within the last three years and you received two doses of the Tetanus Toxoid (TT) or Tetanus-diphtheria (Td) vaccine then, you will likely only need one booster dose during this pregnancy. If it has been longer than three years, or if your immunization history is incomplete, you will need two doses spaced at least four weeks apart. Please consult your doctor to review your previous vaccination records and safely schedule your shot.