近十几年来，不仅发达国家婚前性行为发生率呈不断上升趋势，许多发展中国家（包括中国），未婚性行为发生率也在不断上升〔１～５〕，首次性行为年龄也呈提前趋势，由此导致未婚妊娠、早育、早婚、人工流产和性病等发生率上升。这不仅严重危害未婚青年的健康，也给社会带... In the past decade or so, not only the incidence of premarital sex in developed countries has been on the rise, but many developing countries (including China) and the incidence of unmarried behaviors have also been on the rise [1-5], with the first sexual behavior showing an earlier trend , Resulting in an increase in the incidence of unmarried pregnancy, early childbirth, early marriage, induced abortion and sexually transmitted diseases. This not only seriously jeopardizes the health of unmarried youth, but also gives the community a ...