There are about one million births in Thailand each year. At King Chulalongkorn Memorial Hospital, there are about 10,000 deliveries per year. In 2001-2005, 53% of live births were by spontaneous vaginal delivery, 36% by cesarean delivery, 7.5% by forceps extraction, and 3% by vacuum extraction. Postpartum sexual relations before postpartum visit can cause unplanned pregnancy and genital tract infection. However, a few studies have addressed this issue. Moreover, the studies in Thailand were limited due to culture and tradition. Previous studies of sexual function after childbirth report significant increase perineal pain, dyspareunia, and sexual problems associated with assisted vaginal delivery. Some studies show no difference in sexual function between women with cesarean delivery and spontaneous vaginal delivery. However, most studies had limitations in the method of measuring female sexual function. The Female Sexual Function Index (FSFI) was developed to evaluate female sexual function. The FSFI is a 19-item questionnaire and is used as a brief, multidimensional self-report instrument for assessing the key dimensions of sexual function in women. The questionnaire was designed and validated for assessment of female sexual function and quality of life in most clinical trials or epidemiological studies.