Background <p>To determine the factors affecting placental localization and to examine the effect of placental location on obstetric outcomes in patients who were transferred from fresh embryos and frozen-thawed embryos.</p> Methods <p>This study was conducted with computer-based database records of 688 patients who became pregnant by in vitro fertilization (IVF). All of the patients included in the study were followed up and delivered in our institution. There were 232 patients who underwent fresh embryo (FE) transfer and 97 patients who underwent frozen-thawed embryo (FTE) transfer. The demographic and therapeutic characteristics of the patients, obstetric outcomes, the relationships between placental location and perinatal outcomes were compared between both groups. The relationship between placental location and perinatal outcomes was estimated using multinomial logistic regression analysis.</p> Results <p>FE cycles were associated with preterm birth (<i>p</i> = 0.022), small gestational age fetus (SGA) (<i>p</i> = 0.014), and premature rupture of membranes (<i>p</i> = 0.004). FTE cycles were associated with gestational hypertension (<i>p</i> = 0.033). There was no difference between the two groups in terms of placental location (<i>p</i> = 0.28). Decentralized locations of the placenta were associated with preterm delivery in the FE group (<i>p</i> = 0.008). After adjusting for maternal age, parity, smoking, body mass index, and embryo transfer cycle, the risk of postpartum hemorrhage in the lower placenta (aOR = 8.6) and the risk of fetal growth restriction (aOR = 3.54) and minor anomalies in the lateral placenta (aOR = 3.61) were increased.</p> Conclusion <p>FE and FTE transfer had no effect on placental localization. However, embryo transfer preference may be associated with preterm birth, small gestational age fetus, premature rupture of membranes, gestational hypertension.</p>