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,” Ms. 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,” Ms. Armstrong noted.
“We were not surprised by the findings; they aligned with previous findings and confirm the overall safety of intrauterine devices,” said Ms. 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 Ms. 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,” Dr. 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,” Dr. 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. Ms. Armstrong and several coauthors disclosed support from Bayer during the study. Dr. Krishna had no relevant disclosures.