evidence: ABSTRACT: In the United States, more than one half of pregnancies are unintended, with 3 in 10 women having an abortion by age 45 years 1. In 2008, 1.2 million abortions occurred in the United States, of which 6.2% took place between 13 weeks of gestation and 15 weeks of gestation, and 4.0% took place at 16 weeks of gestation or later 2 3. Only 1.3% of abortions are performed at 21 weeks of gestation or later 4. The proportion of abortions performed in the second trimester, usually defined as between 13 weeks of gestation and 26 weeks of gestation (as calculated from the last menstrual period), has remained stable during the past two decades 4. The purpose of this document is to provide evidence-based guidelines for the medical and surgical methods of second-trimester termination as well as for the management of associated complications. [...] By reading this page you agree to ACOG's Terms and Conditions. Read terms Nonmembers: Subscribe now to access exclusive ACOG Clinical content, including: