Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight: A Secondary Analysis of an Individual Participant Data Meta-analysis

Ngaire H Anderson, Adrienne Gordon, Minglan Li, Robin S Cronin, John MD Thompson, Camille H Raynes-Greenow, Alexander EP Heazell, Tomasina Stacey, Vicki M Culling, Jessica Wilson, Lisa M Askie, Edwin A Mitchell, Lesley ME McCowan

Research output: Contribution to journalArticle

Abstract

Importance  Supine maternal position in the third trimester is associated with reduced uterine blood flow and increased risk of late stillbirth. As reduced uterine blood flow is also associated with fetal growth restriction, this study explored the association between the position in which pregnant women went to sleep and infant birth weight.

Objective  To examine the association between supine position when going to sleep in women after 28 weeks of pregnancy and lower birth weight and birth weight centiles.

Design, Setting, and Participants  Prespecified subgroup analysis using data from controls in an individual participant data meta-analysis of 4 case-control studies investigating sleep and stillbirth in New Zealand, Australia, and the United Kingdom. Participants were women with ongoing pregnancies at 28 weeks’ gestation or more at interview.

Main Outcomes and Measures  The primary outcome was adjusted mean difference (aMD) in birth weight. Secondary outcomes were birth weight centiles (INTERGROWTH-21st and customized) and adjusted odds ratios (aORs) for birth weight less than 50th and less than 10th centile (small for gestational age) for supine vs nonsupine going-to-sleep position in the last 1 to 4 weeks, adjusted for variables known to be associated with birth size.

Results  Of 1760 women (mean [SD] age, 30.25 [5.46] years), 57 (3.2%) reported they usually went to sleep supine during the previous 1 to 4 weeks. Adjusted mean (SE) birth weight was 3410 (112) g among women who reported supine position and 3554 (98) g among women who reported nonsupine position (aMD, 144 g; 95% CI, −253 to −36 g; P = .009), representing an approximate 10-percentile reduction in adjusted mean INTERGROWTH-21st (48.5 vs 58.6; aMD, −10.1; 95% CI, −17.1 to −3.1) and customized (40.7 vs 49.7; aMD, −9.0; 95% CI, −16.6 to −1.4) centiles. There was a nonsignificant increase in birth weight at less than the 50th INTERGROWTH-21st centile (aOR, 1.90; 95% CI, 0.83-4.34) and a 2-fold increase in birth weight at less than the 50th customized centile (aOR, 2.12; 95% CI, 1.20-3.76). Going to sleep supine was associated with a 3-fold increase in small for gestational age birth weight by INTERGROWTH-21st standards (aOR, 3.23; 95% CI, 1.37-7.59) and a nonsignificant increase in small for gestational age birth weight customized standards (aOR, 1.63; 95% CI, 0.77-3.44).

Conclusions and Relevance  This study found that going to sleep in a supine position in late pregnancy was independently associated with reduced birth weight and birth weight centile. This novel association is biologically plausible and likely modifiable. Public health campaigns that encourage women in the third trimester of pregnancy to settle to sleep on their side have potential to optimize birth weight.

LanguageEnglish
Number of pages11
JournalJAMA network open
Volume2
Issue number10
DOIs
Publication statusPublished - 2 Oct 2019

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Birth Weight
Meta-Analysis
Sleep
Pregnancy
Supine Position
Gestational Age
Stillbirth
Third Pregnancy Trimester
Fetal Development
Health Promotion
New Zealand
Case-Control Studies
Pregnant Women
Public Health
Odds Ratio
Mothers
Outcome Assessment (Health Care)
Parturition
Interviews

Cite this

H Anderson, Ngaire ; Gordon, Adrienne ; Li, Minglan ; S Cronin, Robin ; MD Thompson, John ; H Raynes-Greenow, Camille ; EP Heazell, Alexander ; Stacey, Tomasina ; M Culling, Vicki ; Wilson, Jessica ; M Askie, Lisa ; A Mitchell, Edwin ; ME McCowan, Lesley. / Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight : A Secondary Analysis of an Individual Participant Data Meta-analysis. In: JAMA network open. 2019 ; Vol. 2, No. 10.
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abstract = "Importance  Supine maternal position in the third trimester is associated with reduced uterine blood flow and increased risk of late stillbirth. As reduced uterine blood flow is also associated with fetal growth restriction, this study explored the association between the position in which pregnant women went to sleep and infant birth weight.Objective  To examine the association between supine position when going to sleep in women after 28 weeks of pregnancy and lower birth weight and birth weight centiles.Design, Setting, and Participants  Prespecified subgroup analysis using data from controls in an individual participant data meta-analysis of 4 case-control studies investigating sleep and stillbirth in New Zealand, Australia, and the United Kingdom. Participants were women with ongoing pregnancies at 28 weeks’ gestation or more at interview.Main Outcomes and Measures  The primary outcome was adjusted mean difference (aMD) in birth weight. Secondary outcomes were birth weight centiles (INTERGROWTH-21st and customized) and adjusted odds ratios (aORs) for birth weight less than 50th and less than 10th centile (small for gestational age) for supine vs nonsupine going-to-sleep position in the last 1 to 4 weeks, adjusted for variables known to be associated with birth size.Results  Of 1760 women (mean [SD] age, 30.25 [5.46] years), 57 (3.2{\%}) reported they usually went to sleep supine during the previous 1 to 4 weeks. Adjusted mean (SE) birth weight was 3410 (112) g among women who reported supine position and 3554 (98) g among women who reported nonsupine position (aMD, 144 g; 95{\%} CI, −253 to −36 g; P = .009), representing an approximate 10-percentile reduction in adjusted mean INTERGROWTH-21st (48.5 vs 58.6; aMD, −10.1; 95{\%} CI, −17.1 to −3.1) and customized (40.7 vs 49.7; aMD, −9.0; 95{\%} CI, −16.6 to −1.4) centiles. There was a nonsignificant increase in birth weight at less than the 50th INTERGROWTH-21st centile (aOR, 1.90; 95{\%} CI, 0.83-4.34) and a 2-fold increase in birth weight at less than the 50th customized centile (aOR, 2.12; 95{\%} CI, 1.20-3.76). Going to sleep supine was associated with a 3-fold increase in small for gestational age birth weight by INTERGROWTH-21st standards (aOR, 3.23; 95{\%} CI, 1.37-7.59) and a nonsignificant increase in small for gestational age birth weight customized standards (aOR, 1.63; 95{\%} CI, 0.77-3.44).Conclusions and Relevance  This study found that going to sleep in a supine position in late pregnancy was independently associated with reduced birth weight and birth weight centile. This novel association is biologically plausible and likely modifiable. Public health campaigns that encourage women in the third trimester of pregnancy to settle to sleep on their side have potential to optimize birth weight.",
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author = "{H Anderson}, Ngaire and Adrienne Gordon and Minglan Li and {S Cronin}, Robin and {MD Thompson}, John and {H Raynes-Greenow}, Camille and {EP Heazell}, Alexander and Tomasina Stacey and {M Culling}, Vicki and Jessica Wilson and {M Askie}, Lisa and {A Mitchell}, Edwin and {ME McCowan}, Lesley",
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H Anderson, N, Gordon, A, Li, M, S Cronin, R, MD Thompson, J, H Raynes-Greenow, C, EP Heazell, A, Stacey, T, M Culling, V, Wilson, J, M Askie, L, A Mitchell, E & ME McCowan, L 2019, 'Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight: A Secondary Analysis of an Individual Participant Data Meta-analysis', JAMA network open, vol. 2, no. 10. https://doi.org/10.1001/jamanetworkopen.2019.12614

Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight : A Secondary Analysis of an Individual Participant Data Meta-analysis. / H Anderson, Ngaire ; Gordon, Adrienne ; Li, Minglan ; S Cronin, Robin; MD Thompson, John ; H Raynes-Greenow, Camille ; EP Heazell, Alexander ; Stacey, Tomasina; M Culling, Vicki ; Wilson, Jessica; M Askie, Lisa ; A Mitchell, Edwin ; ME McCowan, Lesley.

In: JAMA network open, Vol. 2, No. 10, 02.10.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight

T2 - JAMA network open

AU - H Anderson, Ngaire

AU - Gordon, Adrienne

AU - Li, Minglan

AU - S Cronin, Robin

AU - MD Thompson, John

AU - H Raynes-Greenow, Camille

AU - EP Heazell, Alexander

AU - Stacey, Tomasina

AU - M Culling, Vicki

AU - Wilson, Jessica

AU - M Askie, Lisa

AU - A Mitchell, Edwin

AU - ME McCowan, Lesley

PY - 2019/10/2

Y1 - 2019/10/2

N2 - Importance  Supine maternal position in the third trimester is associated with reduced uterine blood flow and increased risk of late stillbirth. As reduced uterine blood flow is also associated with fetal growth restriction, this study explored the association between the position in which pregnant women went to sleep and infant birth weight.Objective  To examine the association between supine position when going to sleep in women after 28 weeks of pregnancy and lower birth weight and birth weight centiles.Design, Setting, and Participants  Prespecified subgroup analysis using data from controls in an individual participant data meta-analysis of 4 case-control studies investigating sleep and stillbirth in New Zealand, Australia, and the United Kingdom. Participants were women with ongoing pregnancies at 28 weeks’ gestation or more at interview.Main Outcomes and Measures  The primary outcome was adjusted mean difference (aMD) in birth weight. Secondary outcomes were birth weight centiles (INTERGROWTH-21st and customized) and adjusted odds ratios (aORs) for birth weight less than 50th and less than 10th centile (small for gestational age) for supine vs nonsupine going-to-sleep position in the last 1 to 4 weeks, adjusted for variables known to be associated with birth size.Results  Of 1760 women (mean [SD] age, 30.25 [5.46] years), 57 (3.2%) reported they usually went to sleep supine during the previous 1 to 4 weeks. Adjusted mean (SE) birth weight was 3410 (112) g among women who reported supine position and 3554 (98) g among women who reported nonsupine position (aMD, 144 g; 95% CI, −253 to −36 g; P = .009), representing an approximate 10-percentile reduction in adjusted mean INTERGROWTH-21st (48.5 vs 58.6; aMD, −10.1; 95% CI, −17.1 to −3.1) and customized (40.7 vs 49.7; aMD, −9.0; 95% CI, −16.6 to −1.4) centiles. There was a nonsignificant increase in birth weight at less than the 50th INTERGROWTH-21st centile (aOR, 1.90; 95% CI, 0.83-4.34) and a 2-fold increase in birth weight at less than the 50th customized centile (aOR, 2.12; 95% CI, 1.20-3.76). Going to sleep supine was associated with a 3-fold increase in small for gestational age birth weight by INTERGROWTH-21st standards (aOR, 3.23; 95% CI, 1.37-7.59) and a nonsignificant increase in small for gestational age birth weight customized standards (aOR, 1.63; 95% CI, 0.77-3.44).Conclusions and Relevance  This study found that going to sleep in a supine position in late pregnancy was independently associated with reduced birth weight and birth weight centile. This novel association is biologically plausible and likely modifiable. Public health campaigns that encourage women in the third trimester of pregnancy to settle to sleep on their side have potential to optimize birth weight.

AB - Importance  Supine maternal position in the third trimester is associated with reduced uterine blood flow and increased risk of late stillbirth. As reduced uterine blood flow is also associated with fetal growth restriction, this study explored the association between the position in which pregnant women went to sleep and infant birth weight.Objective  To examine the association between supine position when going to sleep in women after 28 weeks of pregnancy and lower birth weight and birth weight centiles.Design, Setting, and Participants  Prespecified subgroup analysis using data from controls in an individual participant data meta-analysis of 4 case-control studies investigating sleep and stillbirth in New Zealand, Australia, and the United Kingdom. Participants were women with ongoing pregnancies at 28 weeks’ gestation or more at interview.Main Outcomes and Measures  The primary outcome was adjusted mean difference (aMD) in birth weight. Secondary outcomes were birth weight centiles (INTERGROWTH-21st and customized) and adjusted odds ratios (aORs) for birth weight less than 50th and less than 10th centile (small for gestational age) for supine vs nonsupine going-to-sleep position in the last 1 to 4 weeks, adjusted for variables known to be associated with birth size.Results  Of 1760 women (mean [SD] age, 30.25 [5.46] years), 57 (3.2%) reported they usually went to sleep supine during the previous 1 to 4 weeks. Adjusted mean (SE) birth weight was 3410 (112) g among women who reported supine position and 3554 (98) g among women who reported nonsupine position (aMD, 144 g; 95% CI, −253 to −36 g; P = .009), representing an approximate 10-percentile reduction in adjusted mean INTERGROWTH-21st (48.5 vs 58.6; aMD, −10.1; 95% CI, −17.1 to −3.1) and customized (40.7 vs 49.7; aMD, −9.0; 95% CI, −16.6 to −1.4) centiles. There was a nonsignificant increase in birth weight at less than the 50th INTERGROWTH-21st centile (aOR, 1.90; 95% CI, 0.83-4.34) and a 2-fold increase in birth weight at less than the 50th customized centile (aOR, 2.12; 95% CI, 1.20-3.76). Going to sleep supine was associated with a 3-fold increase in small for gestational age birth weight by INTERGROWTH-21st standards (aOR, 3.23; 95% CI, 1.37-7.59) and a nonsignificant increase in small for gestational age birth weight customized standards (aOR, 1.63; 95% CI, 0.77-3.44).Conclusions and Relevance  This study found that going to sleep in a supine position in late pregnancy was independently associated with reduced birth weight and birth weight centile. This novel association is biologically plausible and likely modifiable. Public health campaigns that encourage women in the third trimester of pregnancy to settle to sleep on their side have potential to optimize birth weight.

KW - Sleep position

KW - Birthweight

KW - Small for gestational age

U2 - 10.1001/jamanetworkopen.2019.12614

DO - 10.1001/jamanetworkopen.2019.12614

M3 - Article

VL - 2

JO - JAMA network open

JF - JAMA network open

SN - 2574-3805

IS - 10

ER -