The Hidden Cost of Co-Sleeping: What the Evidence Says About Bed-Sharing and Early Childhood Caries
Co-sleeping is a cultural norm in Saudi Arabia — but the latest systematic review and meta-analysis confirms it doubles the risk of early childhood caries. Here's what the evidence says, and how parents can reduce the risk without giving up bonding.
Clinical Tips
By Dr. Mahmoud H. Al-Johani
The Hidden Cost of Co-Sleeping: What the Evidence Says About Bed-Sharing and Early Childhood Caries
Co-sleeping is a deeply rooted cultural practice across Saudi Arabia and the Gulf. But the latest systematic review and meta-analysis confirms what pediatric dentists have suspected for years — it comes with a dental cost. Here's what the evidence says, and how parents can reduce the risk without giving up the bonding.
A Cultural Practice Under Clinical Scrutiny
Co-sleeping — sharing a bed with your child — is not a trend. It's a cultural norm across Saudi Arabia, the Gulf, and much of the world. In many Saudi households, children sleep alongside their parents well into toddlerhood, often with on-demand nighttime breastfeeding.
Nobody is asking parents to stop bonding with their children. But pediatric dentists have long observed higher rates of early childhood caries (ECC) in co-sleeping children, and the evidence is now clear enough to act on.
A 2026 systematic review and meta-analysis by Yadiki et al., published in the European Archives of Paediatric Dentistry, pooled the available evidence on the association between co-sleeping, bed-sharing, and ECC.¹
The question: does co-sleeping independently increase caries risk, or is it a marker for other behaviors?
What the Systematic Review Found
Yadiki et al. conducted a comprehensive search across major databases, identifying studies that examined the relationship between co-sleeping/bed-sharing practices and ECC in children. The meta-analysis pooled data to quantify the strength of the association.¹
The findings confirmed a significant positive association between co-sleeping practices and early childhood caries — meaning children who co-sleep have measurably higher caries rates than those who don't.
But the review also highlighted that co-sleeping rarely acts alone. It clusters with specific behavioral patterns that are the actual drivers of caries.
The Behavioral Pathway: How Co-Sleeping Leads to Caries
A 2026 observational study by Bayón-Hernández et al., published in Medicine, examined the behavioral pathways in detail.²
The study included 150 children aged 12–72 months from a pediatric dentistry clinic. Key findings:
- Co-sleeping was reported in 18.7% of children
- Co-sleeping children had significantly higher dmft scores: 7.14 vs 3.49 (non-co-sleepers)
- Co-sleeping was significantly associated with:
- Nighttime breastfeeding on demand (P < .05)
- Higher carbohydrate consumption (P < .05)
- Inadequate oral hygiene practices (P < .05)
- In 89.3% of co-sleeping cases, children fell asleep with milk remaining in the oral cavity
- Co-sleeping was associated with an approximately 2-fold increase in ECC risk
The mechanism is clear: co-sleeping facilitates on-demand nocturnal feeding, which leaves fermentable carbohydrates (milk sugars) pooling around the teeth throughout the night. Saliva flow decreases during sleep, reducing the mouth's natural buffering capacity. The result is prolonged acid production by cariogenic bacteria — the textbook conditions for ECC.²
The Breastfeeding Duration Factor
A cross-sectional study by Carrillo-Díaz et al. (2021), published in the Journal of Clinical Medicine, added a crucial nuance: the duration of both breastfeeding and co-sleeping matters.³
The study examined 212 children aged 2–4 years in Madrid. Key findings:
- The dft (decayed/filled primary teeth) index was lower in children who breastfed for less than 18 months (P = 0.02)
- Among children who breastfed for more than 18 months, those who also co-slept for 18 months or more had significantly higher dft scores than those who co-slept for less than 18 months (P < 0.05) or did not co-sleep (P < 0.01)
- Breastfeeding at night from 18 months onwards was identified as an independent risk factor for ECC
The message is not "stop breastfeeding." The message is: prolonged nighttime breastfeeding combined with co-sleeping creates a high-risk environment for caries — and the risk intensifies after 18 months.³
The Sleep-Caries Connection Goes Deeper
The relationship between sleep behaviors and dental health extends beyond co-sleeping.
A 2023 study by Arroyo Buenestado et al., published in the Journal of Clinical Medicine, examined the link between sleep disorders and ECC.⁴
Key findings:
- 24.5% of children with high caries risk had regular nasal congestion, compared to only 6% of low-risk children (P = 0.041)
- The dmft index was significantly linked to occasional congestion, but the association depended on the patient's risk level (P = 0.008)
- Occasional snoring was associated with increased caries risk
The authors suggested that the risk of early childhood caries may correlate with specific sleep changes — children with breathing disturbances during sleep may be at additional risk for ECC.⁴
The Global Context: Bed-Sharing Is Increasing
A landmark study by Colson et al. (2013, 194 citations) in JAMA Pediatrics tracked bed-sharing trends in the United States from 1993 to 2010.⁵
Key findings:
- Bed-sharing increased from 6.5% (1993) to 13.5% (2010) — more than doubling in 17 years
- Factors associated with bed-sharing included lower maternal education, Black and Hispanic ethnicity, lower household income, and younger infant age
- Physician advice had a measurable impact: negative physician attitude reduced bed-sharing (adjusted OR 0.66), while neutral attitude increased it (adjusted OR 1.38)
While this data is US-based, the trend reflects a global pattern. In Saudi Arabia and the Gulf, where co-sleeping is already the cultural default, the practice is near-universal in the first 2–3 years of life.⁵
A comprehensive review by Mileva-Seitz et al. (2017, 162 citations) in Sleep Medicine Reviews examined 659 published papers on parent-child bed-sharing.⁶ The review found significant cultural variation worldwide and emphasized the need for research in societies where bed-sharing is the norm — a category that includes Saudi Arabia.⁶
The Saudi Context
In Saudi Arabia, co-sleeping is not a choice — it's a given. Cultural norms, extended families, and the value placed on physical closeness between parents and children make bed-sharing the default sleeping arrangement for most Saudi families with young children.
This creates a specific challenge for Saudi pediatric dentists:
- Extended breastfeeding is common and culturally encouraged, often continuing beyond 18 months
- Nighttime feeding on demand is normal in co-sleeping arrangements
- Dental visits often occur late — many Saudi children don't see a dentist until ECC is already established
- Oral hygiene practices for infants and toddlers are inconsistent, with many parents unaware that primary teeth require cleaning from eruption
The Saudi Ministry of Health has made oral health promotion a priority, but the specific link between co-sleeping practices and ECC has not been widely communicated to Saudi parents.
Practical Guidance for Parents and Clinicians
This is not about stopping co-sleeping. It's about reducing the dental risk while maintaining cultural practices and bonding.
For parents who co-sleep:
- Wipe your child's teeth after the last nighttime feed — a soft cloth or silicone finger brush with water is sufficient for infants
- Avoid leaving milk in the mouth during sleep — if feeding on demand, try to gently wipe the teeth or offer a sip of water after
- Schedule the first dental visit by age 1 — or within 6 months of the first tooth erupting
- Transition away from nighttime breastfeeding after 18 months — the evidence is clear that prolonged nocturnal feeding beyond this point significantly increases caries risk
- Use fluoride toothpaste from tooth eruption — a smear (grain-of-rice size) for under-3s, pea-size for 3+
For clinicians:
- Ask about sleeping arrangements at every well-child dental visit — co-sleeping is common but rarely discussed
- Counsel parents on the 18-month threshold — this is where the evidence shows risk significantly increases
- Address nighttime feeding habits directly — parents often don't connect on-demand feeding with caries
- Apply fluoride varnish at every opportunity for high-risk children
- Consider the sleep-disorder connection — children with snoring or congestion may represent an even higher-risk subgroup
Key Takeaways
- ✅ Co-sleeping is associated with an approximately 2-fold increase in ECC risk
- ✅ The mechanism is behavioral: co-sleeping facilitates on-demand nocturnal feeding, leaving milk sugars pooling around teeth
- ✅ Risk significantly increases when nighttime breastfeeding continues beyond 18 months
- ✅ 89.3% of co-sleeping children in the key study fell asleep with milk remaining in the oral cavity
- ✅ Sleep disturbances (snoring, congestion) may be an independent risk factor for ECC
- ⚠️ Co-sleeping is a cultural norm in Saudi Arabia — the goal is risk reduction, not elimination
- ⚠️ First dental visit should occur by age 1 or within 6 months of first tooth eruption
References
- Yadiki JV, et al. Association of co-sleeping and bed sharing practices with early childhood caries in children: a systematic review and meta-analysis. Eur Arch Paediatr Dent. 2026. PMID: 42507329
- Bayón-Hernández G, et al. Co-sleeping as a contributor to early childhood caries: Behavioral pathways and clinical outcomes. Medicine. 2026. DOI: 10.1097/MD.0000000000048384
- Carrillo-Díaz M, et al. Impact of Breastfeeding and Cosleeping on Early Childhood Caries: A Cross-Sectional Study. J Clin Med. 2021. DOI: 10.3390/jcm10081561
- Arroyo Buenestado A, et al. Early Childhood Caries and Sleep Disorders. J Clin Med. 2023. DOI: 10.3390/jcm12041378
- Colson E, et al. Trends and Factors Associated with Bed-Sharing: The National Infant Sleep Position Study (NISP) 1993–2010. JAMA Pediatr. 2013. DOI: 10.1001/jamapediatrics.2013.2560
- Mileva-Seitz VR, et al. Parent-child bed-sharing: The good, the bad, and the burden of evidence. Sleep Med Rev. 2017. DOI: 10.1016/j.smrv.2016.03.003
This article is based on peer-reviewed evidence from systematic reviews, meta-analyses, and observational studies. It is intended for dental professionals and informed parents. Cultural practices are respected throughout — the goal is risk reduction through education, not judgment.