Objective: To investigate the prevalence of abnormal Papanicolaou smear in pregnant patients who attend
the Antenatal Care Clinic at Thammasat University Hospital.
Material and Method: Pregnant patients who attended the antenatal care clinic at Thammasat University Hospital from August 2003 to December 2003 were recruited for Papanicolaou test. Patients who had abnormal results of equally or over “abnormal squamous/glandular cells of undetermined significance” were assigned for colposcopy and colposcopic biopsy to confirm the result.
Results: From 500 Papanicolaou smear performed, there were only four patients who had abnormal Pap tests, which were: 2 ASC-US and 2 LSIL. The prevalence of abnormal Pap smear in pregnant patients who attended the antenatal clinic at Thammasat University Hospital was 0.8 percent.
Conclusion: The prevalence of abnormal Papanicolaou smear in pregnant patients attending antenatal care clinic at Thammasat University Hospital was quite low in compares with other literature.

Keywords: Prevalence, Abnormal Pap smear, Pregnancy