Expulsion of intrauterine devices was significantly more likely when the devices were inserted within the first 3 days after delivery compared with later insertions, based on data from more than 300,000 women.
Intrauterine devices are effective contraception, and current guidelines support immediate postpartum IUD insertion as a safe, effective, and convenient option, Mary Anne Armstrong, MA, of Kaiser Permanente Northern California, Oakland, and colleagues wrote. Although IUD expulsion rates are low overall, data from previous studies suggest that timing of insertion may affect expulsion rates, and that breastfeeding may play a role.
In the Association of Perforation and Expulsion of Intrauterine Devices (APEX-IUD) cohort study published in JAMA Network Open, the researchers reviewed data from the electronic health records at four sites; the study population included women aged 50 years and younger who underwent IUD insertion between 2001 and 2018.
The women were grouped by postpartum status and timing of IUD placement: 0-3 days, 4 days to 6 weeks, 6-14 weeks, 14-52 weeks, and nonpostpartum (defined as more than 52 weeks or no evidence of delivery).
The researchers also compared expulsion rates in postpartum women who were and were not breastfeeding at the time of IUD insertion based on clinical records, diagnostic codes, or questionnaires at well-baby visits.
The total study population included 326,658 women with a mean age of 32.0 years; 42% were non-Hispanic White, 17.2% were Hispanic other, 13.0% were Hispanic White, 11.9% were Asian or Pacific Islander, 8.7% were non-Hispanic Black, and 0.2% were Hispanic Black. Approximately 80% of the IUDs were levonorgestrel releasing.
A total of 8,943 expulsions were reported, for an overall expulsion rate of 13.94 per 1,000 person-years.
The adjusted hazard ratios for IUD expulsion were 5.34, 1.22, 1.06, and 1.43 for women with insertion times, respectively, of 0-3 days, 4 days to 6 or fewer weeks, 6-14 weeks, and 14-52 weeks. Women with nonpostpartum IUD insertion served as the referent.
The 5-year cumulative incidence of IUD expulsion was highest with placement between 0 and 3 days post partum and lowest with placement at 6-14 weeks postpartum (10.73% and 3.18%, respectively).
“Within the group with IUD insertions 0-3 days postpartum, the highest expulsion rates were discovered within 12 weeks of insertion, with the highest incidence rate occurring at week 6 (844 per 1,000 person-years), a time women are commonly seen post delivery,” the researchers noted.
In a subcohort of 94,817 women with known breastfeeding status, the 5-year cumulative incidence of expulsion was 3.49% for breastfeeding women and 4.57% for nonbreastfeeding women, with an adjusted HR of 0.71 for breastfeeding versus not breastfeeding.
“While women who accept immediate postpartum IUD placement report high satisfaction rates, information on women’s preferences and satisfaction associated with different timing of postpartum placement would also be helpful to understand the benefit-risk profile,” the researchers wrote in their discussion of the findings. “The fact that most expulsions in the immediate postpartum group occurred early presents an opportunity to mitigate risk of unrecognized expulsion and unintended pregnancy via counseling on signs of expulsion and follow-up examination.”
The study findings were limited by several factors including the potential misclassification of exposures and the primary outcome of expulsion, especially since some postpartum women may be lactating whether or not they are breastfeeding, the researchers noted. Other limitations included the combination of complete and partial expulsions, and the dating of IUD expulsion based on when it came to medical attention, which was not necessarily when it occurred. More data are needed on the potential association between lactational amenorrhea and lower expulsion risk among postpartum women who are breastfeeding.
However, the results were strengthened by the large and diverse study population, the use of linked mother-infant records to identify exposures, and the use electronic health records to identify outcomes, and the data can inform patient counseling for postpartum IUDs, the researchers concluded.
Study Reflects Findings From Europe
“The FDA mandated this study in response to a European study, EURAS-IUD1, a European prospective observational study that enrolled 61,448 participants between 2006 and 2012,” Armstrong said in an interview. In the European study “women breastfeeding at the time of device insertion or with the device inserted at 36 weeks’ postpartum or less had higher risk of uterine perforation. The FDA wanted to know if the risks were similar in the United States population”
The APEX-IUD study was designed to reflect current United States clinical practice. “The aims of APEX-IUD are to evaluate risk of IUD-related uterine perforation and device expulsion among women who are breastfeeding or within 12 months postpartum at insertion. The perforation outcome is addressed in a separate paper,” Armstrong noted.
“We were not surprised by the findings; they aligned with previous findings and confirm the overall safety of intrauterine devices,” said Armstrong. “Data from this study provides IUD expulsion risk estimates that can be used to inform clinical practice and preinsertion counseling. IUD insertions 0-3 days postpartum might decrease the risk of unintended pregnancy and provide more convenience and efficiency for new mothers. This has proven to be especially important during the pandemic. The higher risk of expulsion at 0-3 days post partum must be balanced with the low IUD-related uterine perforation risk to provide a comprehensive picture that aids in clinical decision-making.
“Potential barriers to postpartum IUD placement include lack of provision of education on the range of contraceptive options available during prenatal care and failure or inability of hospital inpatient units to stock the intrauterine devices for use when needed,” said Armstrong.
Looking ahead, “future research could evaluate risk factors for partial versus complete expulsions, the association of preinsertion counseling with recognition of potential expulsions and corresponding IUD failure rates, and whether ultrasound verification of IUD position in the uterus after insertion is associated with expulsion risk,” she said.
Identifying Risk Factors Informs Patient Counseling
“The current study examines breastfeeding at time of IUD insertion as a risk factor for expulsion,” Iris Krishna, MD, of Emory University, Atlanta, said in an interview. “There is biologic plausibility that breastfeeding may be a risk factor of IUD expulsion. Breastfeeding stimulates secretion of oxytocin, a hormone which plays a key role in the contraction of the uterus during labor and uterine involution postpartum. It also plays a key role in the contraction of milk ducts to allow for milk letdown. Because of its dual role some mothers may occasionally report uterine cramping with breastfeeding. Prior studies have suggested that breastfeeding may be associated with an increased risk of uterine perforation with postpartum IUD placement, but how breastfeeding may contribute to risk of IUD expulsion has not been studied extensively.”
The current data are consistent with previous studies suggesting the highest risk of IUD expulsion is with placement in the immediate postpartum period (0-3 days). “In a subcohort analysis by breastfeeding status, the risk of IUD expulsion was lower for women who were breastfeeding versus not breastfeeding;” however, “these findings may be due to amenorrhea that can also be seen with breastfeeding,” Krishna said. “Menstrual bleeding is an independent risk factor for IUD expulsion and not having menstrual bleeding while breastfeeding may lower risk of expulsion.
“Patients should be counseled on the benefits of immediate postpartum IUD placement, the risk of IUD expulsion, and alternative contraception options to be able to make an informed decision about the right contraception for them,” Krishna emphasized. “Clinicians can reassure patients that the uterine cramping they may feel while breastfeeding does not appear to increase the risk of IUD expulsion and that the amenorrhea that may result from breastfeeding also may lower the risk of IUD expulsion.”
The study was supported by Bayer through support to RTI Health Solutions, Kaiser Permanente Northern California, Kaiser Permanente Southern California, Kaiser Permanente Washington, and the Regenstrief Institute. Armstrong and several coauthors disclosed support from Bayer during the study. Krishna had no relevant disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
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