- Back-sleeping in the late third trimester is associated with reduced birth weight.
- Encouraging side sleeping has the potential to increase birth weight.
Why this matters
- Sleeping on the back (supine maternal going-to-sleep position) has been associated with vena caval and aortic compression that reduces uterine artery blood flow and decreases placental perfusion.
- Going-to-sleep position is the position women maintain for the longest duration throughout the night.
- 3.2% reported that they went to sleep supine during the previous 1-4 weeks.
- Participants who reported they went to sleep in the supine position had lower adjusted mean difference in birth weights (144; P=.009) compared with those who went to sleep on their sides.
- Retrospective cohort study.
- Cohort taken from the control group of the Collaborative Individual Participant Data Meta-analysis of Sleep and Stillbirth study population (n=1760).
- Primary outcome was the adjusted mean difference in birth weight.
- Funding: Trans-Tasman Research Funding Grant by Cure Kids and Red Nose Australia.
- Small numbers of participants in experimental group.
- Difficult to assess time spent in supine position in this cohort.