Episode 9 · Launch seriesLongitudinal cohort studyVideo coming soon⏱ 3:11 video · 📖 1 min read

Bed-Sharing With Your Baby Left No Mark by Age 11

Bilgin et al., Attachment & Human Development, 2024 · Topics: Sleep

⚠ General information only — this page explains one study and isn't medical or parenting advice for your specific child.

Subscribe on YouTube ↗Read the paper (DOI) ↗

What's the short answer?

In 16,599 UK children followed to age 11, bed-sharing at 9 months was not associated with emotional or behaviour symptom trajectories — no link, in either direction. (This study measured development, not infant sleep safety.)

What did the study do?

Using the UK Millennium Cohort Study, the researchers followed 16,599 children and compared those who bed-shared at 9 months with those who didn't, tracking emotional (internalizing) and behaviour (externalizing) symptoms from ages 3 to 11.

What did it find?

Bed-sharing at 9 months was not associated with children's internalizing or externalizing symptom trajectories from ages 3 to 11.
The result was a null finding — no link in either direction — across a very large, long-running cohort.

What it didn't prove

The study measured emotional and behaviour symptoms as children grew — it did NOT measure infant sleep safety outcomes such as SIDS, and it is not a safe-sleep recommendation. A null association also isn't proof that every sleep arrangement is equivalent in every respect.

🌙 One thing to try tonight

Make your sleep-arrangement decision on current safe-sleep guidance and your family's real life — and let go of the fear that bed-sharing at 9 months, by itself, sets your child's behaviour path.

Frequently asked questions

Does this mean bed-sharing is safe?

This study didn't measure safety at all. Sleep-arrangement safety decisions belong with current safe-sleep guidance and your clinician — this paper only speaks to later behaviour symptoms.

What did it actually rule out?

In this cohort, bed-sharing at 9 months did not predict a different emotional or behaviour symptom path through age 11.

📄 The paper at a glance

“Associations between bed-sharing in infancy and childhood internalizing and externalizing symptoms” by Ayten Bilgin, Isabel Morales-Munoz, Catherine Winsper, Dieter Wolke. Attachment & Human Development, 26(5), 403-422, 2024.

DOI: https://doi.org/10.1080/14616734.2024.2380427 ↗ · Video: 3:11 · Coming soon to youtube.com/@ParentingByScience

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The takeaway

Let this paper retire one specific worry — that bed-sharing at 9 months, by itself, sets your child's behaviour path — while safety decisions stay with safe-sleep guidance.

This site explains studies for general information — it isn't medical or parenting advice for your specific child.

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Topic: Sleep All longitudinal cohort study studies Research for babies & toddlers Paper index

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