to the editor: The authors of this article recommend waiting three months after resolution of a known sexually transmitted infection (STI) before inserting an intrauterine device (IUD). In my opinion, there is no evidence to support this restriction. The American College of Obstetricians and Gynecologists recognizes that there is no known optimal time for IUD insertion after the diagnosis of an STI.¹ The Centers for Disease Control and Prevention's U.S. Selected Practice Recommendations and U.S. Medical Eligibility Criteria do not mention any specific amount of time to delay IUD insertion after an STI is diagnosed.² For women at high risk of becoming pregnant, placing an IUD three to four weeks after treatment would be reasonable. The best approach will depend on the individual patient's circumstances.

In reply: We thank Dr. Peña-Robles for the comments regarding our article. Although the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention do not specify an optimal time for IUD insertion after diagnosis and treatment of an STI, that lack of specificity does not provide useful guidance to readers of American Family Physician. On the other hand, the Planned Parenthood Federation recommends against IUD insertion within three months of the diagnosis and treatment of an STI.¹ Because this is the only published recommendation on the issue, it seemed most useful to provide readers with that information. Dr. Peña-Robles' suggestion that IUDs be placed three to four weeks after STI treatment might be equally safe, but there are no published guidelines or studies supporting a shorter time interval.