The research, funded by Cure Kids, is the first stillbirth case control study in the world to look at maternal sleeping patterns. Results showed that the absolute risk of late stillbirth for women who went to sleep on their left was 1.96 per 1,000 compared with 3.93 per 1,000 for those who slept in any other position.
Cure Kids Chair in Child Health Research Professor Ed Mitchell says: “This is a new observation and given that stillbirth rates in New Zealand have not changed in 20 years it is a dramatic result.”
Professor Lesley McCowan, Head of Obstetrics and Gynaecology at the University, explains: “Our findings might be due to restricted blood flow to the baby which can occur when the mother lies on her back or right side for long periods. If confirmed through future studies we may be able to reduce the number of still births by up to a third which is incredibly exciting. We are now trying to obtain funding to conduct this further research.”
The study involved 155 women in Auckland who gave birth to a stillborn baby when they were at least 28 weeks pregnant, and 310 with ongoing pregnancies. Women were asked detailed questions about their sleep position (left side, right side, back or another position) on going to sleep and on waking before pregnancy and during the last month, week, and night before they believed their baby had died. They were also asked about snoring, daytime sleepiness and duration of sleep, and frequency of night-time toilet visits.
The research also found that women who went to the toilet once or less on the last night, and those who slept for longer were more likely to have a stillborn baby.
A significant relationship was also seen between regular day-time sleeping and longer-than-average night time sleeping with late stillbirth risk.
No link was found between snoring or daytime sleepiness with stillbirth risk.
Researcher and midwife, Tomasina Stacey, who undertook this research as her PhD project, says: “Further research is needed as a matter of urgency so that pregnant women can receive the best public health advice about sleep position.”
To date Tomasina has been awarded two prizes related to this research: the young investigator prize at the International Stillbirth Alliance Conference and also the prize for the Best Midwifery Research at the British maternal fetal medicine conference, at which she is presenting her work this week.
The full research paper can be read online at: www.bmj.com/cgi/doi/10.1136/bmj.d3403
An editorial is also availble at: www.bmj.com/cgi/doi/10.1136/bmj.d3659