Results of a noninferiority randomized controlled trial found that immediate postpartum insertion of a levonorgestrel intrauterine device was noninferior to delayed insertion of the device on breastfeeding outcomes.
The study was conducted at the University of Utah and the University of New Mexico Health Sciences Centers. Participants in the study were 18- to 40-year old females who were pregnant, planned to breastfeed, and desired a levonorgestrel intrauterine device postpartum. Patients were randomized (1:1) to receive immediate device insertion postpartum (n=132) or delayed device insertion (n=127), which occurred 4–12 weeks postpartum. The patients were followed continuously for 6 months. Of note, “Only the data analysis team was blinded to the intervention.”
The study authors conducted both a per-protocol analysis as well as an intention-to-treat analysis. “We powered the study for the primary outcome, breastfeeding continuation at 8 weeks, to detect a 15% noninferiority margin between groups, requiring 132 participants in each arm,” noted the authors. Time to lactogenesis was the secondary study outcome, which was analyzed via survival analysis and log rank test.
Results found that 79% of patients in the immediate insertion group reported any breastfeeding at 8 weeks (95% CI: 70, 86), which was noninferior to the 84% of patients in the delayed insertion group (95% CI: 76, 91). The study authors noted, “The 5% difference in breastfeeding continuation at 8 weeks between the groups fell within the noninferiority margin (95% confidence interval, –5.6 to 15%).”
They also reported that the time to lactogenesis (mean ± SD) for patients in the immediate insertion group was 65.3 ± 25.7 hours versus 63.6 ± 21.6 hours for patients in the delayed insertion group. “The mean difference between groups was 1.7 hours (95% confidence interval, –4.8 to 8.2 hours), noninferior by log-rank test,” wrote the authors.
Additional findings of the study included an increased risk of intrauterine device expulsion occurring in the immediate insertion group (n=24, 19%) compared to the delayed insertion group (n=2, 2%; P<0.001). No intrauterine device perforations were reported in either group.
“Our results of noninferior breastfeeding outcomes between women with immediate and delayed postpartum levonorgestrel intrauterine device insertion suggest that immediate postpartum intrauterine device insertion is an acceptable option for women planning to breastfeed and use the levonorgestrel intrauterine device,” concluded the authors.
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