Effects of the immediate postpartum insertion of the etonogestrel implant on the development of breastfed infants: Results from a randomized controlled trial

Abstract

Objectives: To evaluate motor, cognitive, language, and social-emotional development in breastfed infants whose mothers received the etonogestrel (ENG) implant either immediately postpartum or at 6 weeks postpartum.

Methods: This was a secondary analysis from a randomized controlled trial involving 100 postpartum women and their infants. Postpartum women were block-randomized to receive the ENG implant either within 48 h of delivery (early insertion group, n = 50) or at 6 weeks postpartum (delayed insertion group, n = 50). We focused on infant development assessed at 6-8 months and 12-15 months using the Bayley-III Scales of Infant and Toddler Development (BSID-III). The study was conducted at the University Hospital of Ribeirão Preto Medical School, Brazil. Sociodemographic and clinical characteristics were compared using t tests and χ² tests. BSID-III composite scores were analyzed using mixed-effects linear regression.

Results: A total of 79 infants completed at least one developmental assessment. No significant differences in baseline sociodemographic and clinical characteristics were observed between groups. At 6-8 months, BSID-III composite scores across all domains were similar between groups. At 12-15 months, the early insertion group had a significantly higher mean motor score compared with the delayed group (108 ± 11 vs. 99 ± 14, P = 0.003), but no significant differences were found in the other domains.

Conclusion: Immediate postpartum ENG implant insertion did not negatively impact infant development up to 12-15 months.

Clinical trial registration: This study was registered on https://clinicaltrials.gov/, registration number NCT02469454, Link: https://www.

Clinicaltrials: gov/study/NCT02469454?term=NCT02469454%20&rank=1#study-overview; date of registration: June 9, 2015.

Keywords: etonogestrel implant; infant development; long‐acting reversible contraception; postpartum contraception.

FIGURE 1

Flowchart of the study. Early represents etonogestrel implant inserted within 48 h of delivery. Delayed represents etonogestrel implant inserted at 6 weeks postpartum. ^aIn the early insertion group, 23 infants attended both developmental assessments (at 6–8 months and 12–15 months), while 12 attended only one (six attended only the 6–8 months visit and six only the 12–15 months visit). ^bIn the delayed insertion group, 37 infants attended both assessments, and seven attended only one (five attended only the 6–8 months visit and two only the 12–15 months visit).