Sampling of vaginal secretions should not lead to any additional risk or complications beyond that of doing a standard pelvic examination. Certain technical problems, however, may make the specimen difficult to interpret or produce artifactual results.

Clinical factors
The quality of the vaginal secretions being sampled and thus the ability to make an accurate diagnosis can be affected by the following factors:

• Recent menses
• Recent douching
• Recent intravaginal medication
• Recent sexual intercourse–presence of semen
• Recent systemic antibiotics
• Use of lubricants during examination before sampling secretions

All of the above can affect the clinical diagnosis by changing the consistency, amount, and appearance of the vaginal discharge, by affecting the pH of the secretions, and by changing the whiff test. Menses, douching, and semen can increase the pH. Water used to lubricate the speculum can increase the pH, as can the lubricant used in the bimanual examination. Remember to use lubricant only after all samples have been taken, including the Papanicolaou (Pap) smear. In addition, a weakly positive whiff test can be due to the presence of semen or menstrual blood in the vagina. The above factors also potentially affect the laboratory yield. For example, a culture or Gram stain result may be affected by the recent use of systemic antibiotics or intravaginal medications.

Sampling method
The method of sampling also has a few pitfalls. The vaginal sample must be taken with care so as not to contaminate the sample with the cervical secretions. Conversely, when a sample is taken from the cervical os, it is important to remove the swab carefully, avoiding any contact with the vaginal mucosa that will potentially affect the results of the laboratory testing. When samples of cervical secretions are obtained, time should be taken to twirl the swab carefully for a full 10 to 15 seconds (Sweet).

Sample preparation
Although sample preparation is quite easy to perform, the manner in which the saline wet mount and KOH are prepared is important to the success in identifying elements for diagnosis. In general, for saline wet mount a smaller amount of discharge should be used, with relatively more saline to help disperse the epithelial cells. If too little discharge is used, there may not be enough identifying elements to make the diagnosis. If too much is used relative to saline, there will be excessive clumping, making the slide difficult if not impossible to read. For KOH prep, some sources report more success with diagnosis when using relatively more discharge in proportion to KOH because this may increase the number of organisms seen (Eschenbach). In general it is best to read the wet mount and KOH prep as soon as they are prepared, since excess drying of the slide can cause distortion of identifying elements. In addition, trichomonads lose mobility with drying and with variation in temperature beyond 32° to 37° C (Kreiger).

Processing delays
The means by which the sample is stored and handled prior to arrival in the laboratory is vitally important to achieving an accurate result on testing. The laboratory test is only as good as the quality of the sample received by the laboratory. Remember to send the specimen to the laboratory as soon as possible. Follow directions on testing kits whenever possible. When culturing specific organisms remember their individual growth requirements.