When Is the Ideal Time in the Menstrual Cycle for IUD Insertion?
By, MD, MPH, Editor  SYNOPSIS: In this retrospective cohort study, women using the levonorgestrel intrauterine device for noncontraceptive indications had higher expulsion rates (38% vs. 17%, P = 0.03) when insertion occurred on day 1 to day 8 of the menstrual cycle compared to after  day 8. SOURCE: Harris S, Kaneshiro B, Ahn HJ, Saito-Tom L. Timing of insertion affects expulsion in patients using the levonorgestrel 52 mg intrauterine system for noncontraceptive indications. Contraception 2021;103:185-189. In the past, intrauterine devices (IUDs) often were inserted during menses to ensure that the patient was not pregnant. Current guidelines allow for insertion at any time during the menstrual cycle as long as it is reasonably certain the patient is not pregnant.1 The authors of this study wanted to determine if the timing of insertion related to the menstrual cycle made a difference in expulsion rates among women using the IUD for noncontraceptive indications. In this retrospective cohort study, investigators studied women who underwent 52 mg levonorgestrel IUD (LNG-IUD) insertion for abnormal uterine bleeding, dysmenorrhea, or endometrial hyperplasia between Jan. 1, 2009, and Dec. 31, 2010, at all Kaiser-Permanente Hawaii locations. Patients who did not have a follow-up visit were excluded. The primary outcome was IUD expulsion, both complete and partial. Data collected included timing of insertion with respect to last menstrual period (LMP), uterine cavity length in centimeters, reason for insertion, presence of uterine pathology, and patient demographic factors. Patients undergoing IUD insertion after a procedure, such as endometrial biopsy, hysteroscopy, or suction aspiration, also were included. A total of 176 women were included in the study. Expulsion occurred in 39 (22%) patients, with 82% occurring within the first year and 29% occurring in the first 60 days. Women with a known LMP were analyzed (n = 129). Insertions occurring during day 1 to day 8 of the menstrual cycle were associated with a greater number of expulsions (16/42, 38% vs. 8/47, 17%, P = 0.03) compared to after day 8. Additionally, women with a uterine cavity length of 8.5 cm or more had a higher rate of expulsion compared to patients with a cavity length of 8.5 cm or less based on uterine sounding (24/39, 61.5% vs. 15/39, 38.5%, P = 0.01). After excluding women who underwent IUD insertion after a procedure (n = 51), insertion of the IUD during the first eight days of the menstrual cycle resulted in a 3.57 odds of expulsion (95% confidence interval, 1.13, 11.31) after adjusting for dysmenorrhea, uterine cavity length, and uterine pathology. There was no association between IUD expulsion and age, parity, body mass index, or indication for insertion. COMMENTARY  The question of the timing of IUD insertion is important and may differ between IUDs inserted for contraceptive purposes and those inserted to treat gynecologic disorders. The Centers for Disease Control and Prevention (CDC) has published guidelines on the use of IUDs, Selected Practice Recommendations for Contraceptive Use.1 According to the guidelines, the IUD may be inserted any time during the menstrual cycle as long as the woman is reasonably sure she is not pregnant, has no symptoms or signs of pregnancy, and meets any one of the following criteria:  is  7 days after the start of normal menses;  has not had sexual intercourse since the start of last normal menses;  has been correctly and consistently using a reliable method of contraception;  is  7 days after spontaneous or induced abortion;  is within four weeks postpartum;  is fully or nearly fully breastfeeding (exclusively breastfeeding or the vast majority [  85%] of feeds are breastfeeds), amenorrheic, and < 6 months postpartum. The CDC based this recommendation on a systematic review that included eight studies of the copper IUD. This review concluded that the timing of IUD insertion has little effect on longer term outcomes, such as rates of continuation, removal, expulsion, pregnancy, pain at insertion, and bleeding at insertion.2 There were no studies of the LNG-IUD. Whether insertion timing recommendations vary for women who are having the IUD placed for gynecologic purposes is unknown. Among contraceptive patients, the expulsion rate for the LNG-IUD is approximately 4% over six years of use.3 However, there is a concern for a higher expulsion rate when IUDs are placed for abnormal uterine bleeding. This study showed an overall expulsion rate of 22% over the first year, which is very high. Certainly, it makes biologic sense that a patient with heavy menstrual bleeding and/or fibroids with an enlarged uterine cavity may have a higher risk of IUD expulsion. This study is intriguing because the expulsion rate was higher when the IUD was placed during menses, and the authors suggested that insertion during this time be avoided. In our practice, we place IUDs at any time in the menstrual cycle, whether for contraception or gynecologic disorders. Logistically, it is difficult to schedule appointments during certain times of the menstrual cycle and may be a barrier to care. I do not think this one study of 176 women with a variety of different gynecologic conditions would change my practice. Nevertheless, we should counsel women who are having the LNG-IUD placed for gynecologic disorders that their risk of expulsion is higher than baseline. More research in this area would be welcome. REFERENCES