Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Aug;124(2 Pt 1):274-283.
doi: 10.1097/AOG.0000000000000388.

Birth weight percentile and the risk of term perinatal death

Alexandros A Moraitis  1 , Angela M Wood, Michael Fleming, Gordon C S Smith
Affiliations

Birth weight percentile and the risk of term perinatal death

Alexandros A Moraitis et al. Obstet Gynecol. 2014 Aug.

Abstract

Objective: To estimate the association between birth weight percentile and the risk of perinatal death at term in relation to the cause of death.

Methods: We performed a retrospective cohort study of all term singleton births in delivery units in Scotland between 1992 and 2008 (n=784,576), excluding perinatal deaths ascribed to congenital anomaly.

Results: There were 1,700 perinatal deaths in the cohort, which were not the result of congenital anomaly (21.7/10,000 women at term). We observed a reversed J-shaped association between birth weight percentile and the risk of antepartum stillbirth in all women, but the associations significantly differed (P<.001) according to smoking status. The highest risk (adjusted odds ratio referent to 21st-80th percentile, 95% confidence interval) among nonsmokers was for birth weight third or less percentile (10.5, 8.2-13.3), but there were also positive associations for birth weight percentiles 4th-10th (3.8, 3.0-4.8), 11th-20th (1.9, 1.5-2.4), and 98th-100th (1.8, 1.3-2.4). Among smokers, the associations with being small were weaker and the associations with being large were stronger. We also observed a reversed J-shaped association between birth weight percentile and the risk of delivery-related perinatal death (ie, intrapartum stillbirth or neonatal death), but there was no interaction with smoking. The highest risk was for birth weight greater than the 97th percentile (2.3, 1.6-3.3), but there were also associations with third or less percentile (2.1, 1.4-3.1), 4th-10th (1.8, 1.4-2.4), and 11th-20th (1.5, 1.2-2.0). Analysis of the attributable fraction indicated that approximately one in three antepartum stillbirths and one in six delivery-related deaths at term could be related to birth weight percentile outside the range 21st-97th percentile.

Conclusion: Effective detection of variation in fetal size at term has potential as a screening test for the risk of perinatal death.

Level of evidence: II.

PubMed Disclaimer

References

    1. MacDorman MF, Kirmeyer S. Fetal and perinatal mortality, United States, 2005. Natl Vital Stat Rep 2009;57:1–19.
    1. The Stillbirth Collaborative Research Network Writing Group. Association between stillbirth and risk factors known at pregnancy confirmation. JAMA 2011;306:2469–79.
    1. McIntire DD, Bloom SL, Casey BM, Leveno KJ. Birth weight in relation to morbidity and mortality among newborn infants. N Engl J Med 1999;340:1234–8.
    1. Clausson B, Gardosi J, Francis A, Cnattingius S. Perinatal outcome in SGA births defined by customised versus population-based birthweight standards. BJOG 2001;108:830–4.
    1. Chard T, Yoong A, Macintosh M. The myth of fetal growth retardation at term. Br J Obstet Gynaecol 1993;100:1076–81.

Publication types