The risk of fetal death in nonanomalous pregnancies affected by polyhydramnios

Rachel A Pilliod; Jessica M Page; Richard M Burwick; Anjali J Kaimal; Yvonne W Cheng; Aaron B Caughey

doi:10.1016/j.ajog.2015.05.022

The risk of fetal death in nonanomalous pregnancies affected by polyhydramnios

Am J Obstet Gynecol. 2015 Sep;213(3):410.e1-6. doi: 10.1016/j.ajog.2015.05.022. Epub 2015 May 14.

Authors

Rachel A Pilliod¹, Jessica M Page², Richard M Burwick³, Anjali J Kaimal⁴, Yvonne W Cheng⁵, Aaron B Caughey³

Affiliations

¹ Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Massachusetts General Hospital, Boston, MA. Electronic address: rpilliod@partners.org.
² Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, UT.
³ Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, OR.
⁴ Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA.
⁵ Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of California, Davis, School of Medicine, Sacramento, CA.

PMID: 25981851
DOI: 10.1016/j.ajog.2015.05.022

Abstract

Objective: The objective of the study was to evaluate the ongoing risk of intrauterine fetal demise (IUFD) in nonanomalous pregnancies affected by polyhydramnios.

Study design: We analyzed a retrospective cohort of all singleton, nonanomalous births in California between 2005 and 2008 as recorded in a statewide birth certificate registry. We included all births between 24+0 and 41+6 weeks' gestational age, excluding multiple gestations, major congenital anomalies, and pregnancies affected by oligohydramnios. Polyhydramnios was identified by International Classification of Diseases, ninth revision, codes. χ(2) tests were used to compare the dichotomous outcomes, and multivariable logistic regression analyses were then performed to control for potential confounders. We analyzed the data for pregnancies affected and unaffected by polyhydramnios. The IUFD risk was expressed as a rate per 10,000.

Results: The risk of IUFD in pregnancies affected by polyhydramnios was greater at every gestational age compared with unaffected pregnancies. The IUFD risk in pregnancies affected by polyhydramnios was more than 7 times higher than unaffected pregnancies at 37 weeks at a rate of 18.0 (95% confidence interval [CI], 9.0-32.6) vs 2.4 (95% CI, 2.0-2.5) and was 11-fold higher by 40 weeks' gestational age at a rate of 66.3 (95% CI, 10.8-68.6) vs 6.0 (95% CI, 5.1-6.3) in unaffected pregnancies. When adjusted for multiple confounding variables, the presence of polyhydramnios remained associated with an increased odds of IUFD in nonanomalous singleton pregnancies, with an adjusted odds ratio of 5.5 (95% CI, 4.1-7.6).

Conclusion: Ongoing risk of IUFD is greater in low-risk pregnancies affected by polyhydramnios at all gestational ages compared with unaffected pregnancies with the greatest increase in risk at term. Although further study is needed to explore the underlying etiology of polyhydramnios in these cases, the identification of polyhydramnios alone may warrant increased antenatal surveillance.

Keywords: antenatal testing; intrauterine fetal demise; polyhydramnios; stillbirth.

MeSH terms

Adult
California
Cohort Studies
Female
Fetal Death / etiology*
Humans
Logistic Models
Male
Polyhydramnios / mortality*
Pregnancy
Registries
Retrospective Studies
Risk Factors