In this paper, an epidemiological analysis was performed, using an international data set, exclusively on the expulsion problem associated with postpartum IUD insertions. The insertor's experience in postplacental insertions is probably an important determining factor for IUD expulsions. Immediate insertions (within 10 minutes after placental delivery) are possibly associated with lower expulsion rates than later insertions (eg. two to 72 hours after placental delivery) during the woman's postpartum hospitalisation. No significant differences were detected between the standard Lippes Loop D and Copper T IUDs and their counterpart Delta devices specifically designed for postpartum use, between the two types of Delta device or between the hand and inserter methods. A case-control analysis also did not detect any significant association between IUD expulsions and mild complications occurring or management performed during the third stage of labor and delivery. The practical implications of these findings, the methodologic problems of this analysis and future research strategies are also discussed.