The objective of this research project is to use qualitative and quantitative research methods to investigate women’s ambivalence about committing to long-term contraception when they present for EC and to assess how the selection of the copper IUD versus oral LNG for EC affects future use of an effective method of contraception. The aims of our multi-disciplinary Family Planning Research Group are: Aim 1: Determine factors that shape women’s decisions about using the copper IUD and oral LNG for EC. Aim 2: Compare 3- and 6-month rates of adoption/continuation of effective contraception between women selecting the copper IUD vs. those selecting oral LNG for EC. The qualitative portion of the study addresses Aim 1 and involved in-depth interviews with 14 women who selected the copper IUD for EC and 14 women who selected oral LNG for EC. The qualitative study yielded the following results: Long-term birth control methods are viewed as primarily related to long-term sexual relationships, few women are aware of the copper IUD’s function as EC, and although being pregnant would not fit with these women’s current views of themselves, many participants engage in unprotected sex. Regarding the quantitative research addressed in the second aim, the SFP support for this project enabled us to enroll 280 participants. This was enough to assess an outcome of differences in use of effective contraception at the end of 6 months. We were able to segue SFP funding into additional support obtained from the NICHD (1R21HD063028). With additional grant sponsorship we were able to enroll 549 women in the trial, enough to power the study to assess differences in unplanned pregnancies between the two groups. Of these 549, 176 women actually received the IUD and 373 women received oral LNG. To date, in the IUD group there have been 11 expulsions and 19 removals. There have been 21 pregnancies. By intention to treat analysis there have been 16 pregnancies in the oral LNG group and 5 in the IUD group. However, only one of the pregnancies in the IUD group actually occurred with an IUD in place. At 6 months from presentation by intention to treat analysis with data available for 88 IUD users and 94 oral LNG users contraceptive use is as follows: In the IUD group 58 women (66%) are using a highly effective method (typical efficacy >98%), 6 (6.8% are using an effective method (typical use efficacy 92-98%), 18 (20.5%) are using a less effective method (typical use efficacy <92%) and 6 (6.8%) are using no method. The corresponding numbers for the oral LNG group are 7 (7.5%), 32 (34.0%), 37 (39.4%) and 18 (19.2 %). The two groups have significantly different use of contraceptive methods (p<0.001). We will continue to follow all the participants enrolled for year and report our findings at the annual SFP meeting and in an appropriate journal.