Pregnant women who sleep on their back (supine sleep) may be at an increased risk of stillbirth, a new study carried out in Ghana has warned.
According to the study led by a University of Michigan researcher, pregnant women in Ghana who slept on their back were at an increased risk of stillbirth compared to women who did not sleep on their back.
Researchers found that supine sleep increased the risk of low birth weight by a factor of 5 and that it was the low birth weight that explained the high risk for stillbirth in these women.
The study's senior author, Louise O'Brien, associate professor in U-M's Sleep Disorders Center, said that although this study was conducted in a maternity hospital in Ghana - a country that has high perinatal mortality - a recent case-control study from New Zealand also found a link between maternal supine sleep and stillbirth.
Stillbirth is a traumatic event that occurs in about 2-5 babies out of every 1,000 babies born in high-income countries. In low income countries, such as those in Africa, about 20-50 babies out of every 1,000 babies are stillborn.
"But if maternal sleep position does play a role in stillbirth, encouraging pregnant women everywhere not to sleep on their back is a simple approach that may improve pregnancy outcomes," O'Brien said in the study, published in the International Journal of Gynecology and Obstetrics.
"In Ghana, inexpensive interventions are urgently needed to improve pregnancy outcomes. This is a behaviour that can be modified: encouraging women to avoid sleeping on their back would be a low-cost method to reduce stillbirths in Ghana and other low-income countries," O'Brien added.
O'Brien said that the possibility that supine sleep has a part in low birth weight and subsequently stillbirth is plausible because of uterine compression on the inferior vena cava, resulting in reduced venous filling and cardiac output.
"The data in this study suggests that more than one-quarter of stillbirths might be avoided by altering maternal sleep position," O'Brien said.
