In Laboratory medicine, urine pregnancy test is an easily available diagnostic test in the present day. Only a few recent studies have estimated population pregnancy rates using objective, laboratory-based criteria. Here, the authors performed a study on laboratory-measured pregnancy rates and their correlation to marital status in a tertiary hospital in Thailand. This study can be not only good information in medical aspect but also in social aspect. The data from medical records of the female patients who got diagnostic urine pregnancy test at Division of Laboratory Medicine, King Chulalongkorn Memorial Hospital, Bangkok Thailand during August 2004 to December 2004 were reviewed. Descriptive statistic was used on the data where it was appropriate. There were 1005 medical records reviewed in this study. From total medical records, there was no subject who is younger than 10-years-old. The diagnostic test results were positive in 121 cases (12.0%) and negative in 884 cases (88.0%). Classified by marital status, we found that most were married. The laboratory-measured pregnancy rates in the single and married group are 15.1% and 9.7%, respectively. There is a significant higher rate among the single group. High percentage of pregnancy group can imply for unplanned and teenage pregnancy. On interest, those types of problematic pregnancy can bring both medical and social problems.