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

**Authors:** Mariane Nunes de Nadai, Maria Beatriz Martins Linhares, Juliana Cunha de Lima Rodrigues Sisdeli, Lilian Sheila de Melo Pereira do Carmo, Giordana Campos Braga, Leticia Sanchez Ferreira, Silvana Maria Quintana, Carolina Sales Vieira

PMC · DOI: 10.1002/ijgo.70291 · International Journal of Gynaecology and Obstetrics · 2025-06-09

## TL;DR

A study found that inserting a contraceptive implant immediately after childbirth did not harm infant development up to 12-15 months.

## Contribution

This is the first study to show that early postpartum contraceptive use does not negatively affect infant development.

## Key findings

- Infants in both groups had similar developmental scores at 6-8 months.
- At 12-15 months, infants whose mothers had early implants had higher motor scores.
- No negative effects on cognitive, language, or social-emotional development were observed.

## Abstract

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.

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 χ
2 tests. BSID‐III composite scores were analyzed using mixed‐effects linear regression.

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.

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

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.

## Linked entities

- **Chemicals:** etonogestrel (PubChem CID 6917715)

## Full-text entities

- **Chemicals:** ENG (MESH:C044815)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

29 references — full list in the complete paper: https://tomesphere.com/paper/PMC12640174/full.md

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Source: https://tomesphere.com/paper/PMC12640174