An endometrial biopsy is contraindicated in any woman who:

• Is pregnant
  If your patient is at risk for becoming pregnant, an endometrial biopsy should not be done more than 14 to 16 days after ovulation, since it may disrupt an early pregnancy. A biopsy done 10 to 14 days after the rise in basal body temperature or luteinizing hormone surge will probably not interfere with implantation.
   
• Has an acute cervicitis or pelvic inflammatory disease
  Instrumentation of an infected cervix could spread the infection into the body of the uterus or the bloodstream.
   
• Has an abnormality in coagulation
  A woman with an uncorrected defect in coagulation may bleed excessively after an endometrial biopsy. Biopsy should be avoided in patients if the bleeding defect cannot be corrected.