BACKGROUND AND PURPOSE: 

• Multiple studies have been conducted that look at sleep position as well as duration and awakenings as risk factors for stillbirth 
• Supine position has been associated with increased stillbirth risk  
• O’Brien et al. (Birth., 2019) examined whether maternal sleep practices are related to late stillbirth

METHODS: 

• International internet-based case-control study  
  • Study of Trends and Associated Risks for Stillbirth (STARS) Consortium 
• Women who had either 
  • Case: Stillbirth ≥28 weeks’ gestation within 30 days before survey completion  
  • Control: Ongoing ≥28 weeks’ gestation or delivered a live born child within 30 days before survey completion  
  • Multifetal pregnancy or fetal anomaly excluded  
  • Matched for gestational age  
• Survey included questions related to  
  • Established risk factors (e.g., smoking, perceived fetal movements) 
  • ‘Novel’ factors such as sleep practices (e.g., position, duration)   
• Sample size calculation  
  • 144 cases and controls needed to detect a difference in odds ratio (OR) of at least 3.0 between the groups 
  • Power of 80%; P = 0.05

RESULTS: 

• 153 stillbirth cases, 480 controls  
• Stillbirth was associated with 
  • Sleeping >9 hours per night in the previous month (aOR 1.75 [95% CI, 1.10-2.79]) 
  • Waking on the right side (aOR 2.27 [95% CI, 1.31-3.92]) 
• Nonrestless sleep (self-reported) in the last month was associated with stillbirth  
  • aOR 1.73 (95% CI, 1.03-2.99)  
• Waking zero or 1 time during the last night of pregnancy was associated with stillbirth  
  • aOR 2.03 (95% CI, 1.24-3.34) 
• No relationship was found with going to sleep position during pregnancy 
  • However, only 2.4% of women reported settling in the supine position (2.4%)

CONCLUSION: 

• The relationship between undisturbed sleep and stillbirth risk is consistent with previous studies  
• Previous studies have found a relationship between both short and long sleep duration and stillbirth  
• The authors suggest that dysregulation of neuroendocrine and autonomic systems related to sleep patterns may contribute to risk of stillbirth and more research in this area is warranted

Learn More – Primary Sources: 

Maternal sleep practices and stillbirth: Findings from an international case-control study

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