Sleep Position, Fetal Growth Restriction, and Late-Pregnancy Stillbirth: The Sydney Stillbirth Study

Gordon, Adrienne FRACP, PhD; Raynes-Greenow, Camille MPH, PhD; Bond, Diana RN; Morris, Jonathan FRANZCOG, PhD; Rawlinson, William FRACP, PhD; Jeffery, Heather FRACP, PhD

doi: 10.1097/AOG.0000000000000627
Contents: Original Research
Journal Club

OBJECTIVE: To identify potentially modifiable risk factors for late-pregnancy stillbirth.

METHODS: This was a population-based matched case–control study of pregnant women at 32 weeks of gestation or greater booked into tertiary maternity hospitals in metropolitan Sydney between January 2006 and December 2011. The case group consisted of women with singleton pregnancies with antepartum fetal death in utero. Women in the control group were matched for booking hospital and expected delivery date with women in the case group. Data collection was performed using a semistructured interview and included validated questionnaires for specific risk factors. Adjusted odds ratios (ORs) were calculated for a priori-specified risk factors using conditional logistic regression.

RESULTS: There were 103 women in the case group and 192 women in the control group. Mean gestation was 36 weeks. Supine sleeping was reported by 10 of 103 (9.7%) of women who experienced late-pregnancy stillbirth and by 4 of 192 (2.1%) of women in the control group (adjusted OR 6.26, 95% confidence interval [CI] 1.2–34). Women who experienced stillbirth were more likely to: have been followed during pregnancy for suspected fetal growth restriction, 11.7% compared with 1.6% (adjusted OR 5.5, 95% CI 1.36–22.5); not be in paid work, 25.2% compared with 9.4% (adjusted OR 2.9, 95% CI 1.1–7.6); and to have not received further education beyond high school, 41.7% compared with 25.5% (adjusted OR 1.9, 95% CI 1.1–3.5). None of the deaths to women who reported supine sleeping were classified as unexplained.

CONCLUSION: This study suggests that supine sleep position may be an additional risk for late-pregnancy stillbirth in an already compromised fetus. The clinical management of suspected fetal growth restriction should be investigated further as a means of reducing late stillbirth.

LEVEL OF EVIDENCE: II

Supine sleep position, suspected fetal growth restriction, unpaid work, and lower education status are potentially modifiable risk factors for late-pregnancy stillbirth.

RPA Newborn Care, Royal Prince Alfred Hospital, Sydney Medical School, Sydney School of Public Health, and the Discipline of Paediatrics and Child Health, University of Sydney, Perinatal Research, Kolling Institute of Medical Research, Sydney University, Royal North Shore Hospital, St Leonards, New South Wales, the University of New South Wales, and South Eastern Area Laboratory Services, Virology Division, Randwick, Australia.

Corresponding author: Adrienne Gordon, FRACP, PhD, RPA Newborn Care, Royal Prince Alfred Hospital, Missenden Road, Camperdown, Sydney NSW 2050, Australia; e-mail: adrienne.gordon@sydney.edu.au.

Supported by the Stillbirth Foundation Australia.

Presented at the 2012 International Conference on Stillbirth, SIDS and Infant Survival, October 4–7, 2012, Baltimore, Maryland.

The authors thank Elizabeth Headley, Angela Carberry, and Rachel Jones for recruitment, data collection, and data entry; Deborah De Wilde, Perinatal Social Worker, for recruitment and data collection; the Principal Investigators at the recruiting hospitals: Professor Michael Peek—Nepean, Professor John Smoleniec—Liverpool, Dr Antonia Shand—Royal Hospital for Women, Professor Jonathan Morris—Royal North Shore, Mater and North Shore Private, Professor Heather Jeffery—Royal Prince Alfred, Dr Janet Vaughan—Canterbury, and Dr Terry McGee—Westmead; and the families who participated in the study and contributed so much at such a difficult time.

Financial Disclosure Ms. Bond received a salary as a Research Officer during the conduct of this study that was paid for with a grant received by the Stillbirth Foundation Australia. Dr. Morris is currently chairman of the board of directors of the Stillbirth Foundation Australia and has been a director since 2008. The other authors did not report any potential conflicts of interest.

© 2015 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.