Am J Perinatol
DOI: 10.1055/s-0041-1735285
SMFM Fellows Research Series

Intrapartum Fetal Electrocardiogram in Small- and Large-for-Gestational Age Fetuses

1  Departments of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois
,
Steven J. Weiner
2  Departments of Obstetrics and Gynecology, George Washington University Biostatistics Center, Washington, District of Columbia
,
George R. Saade
3  Departments of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas
,
4  Departments of Obstetrics and Gynecology, University of Utah Health Sciences Center, Salt Lake City, Utah
,
Sean C. Blackwell
5  Departments of Obstetrics and Gynecology, University of Texas Health Science Center at Houston, McGovern Medical School-Children's Memorial Hermann Hospital, Houston, Texas
,
Uma M. Reddy
6  Departments of Obstetrics and Gynecology, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
,
John M. Thorp Jr.
7  Departments of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
,
Alan T.N. Tita
8  Departments of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
,
Russell S. Miller
9  Departments of Obstetrics and Gynecology, Columbia University, New York City, New York
,
David S. McKenna
10  Departments of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio
,
Edward K.S. Chien
11  Departments of Obstetrics and Gynecology, MetroHealth Medical Center-Case Western Reserve University, Cleveland, Ohio
,
Dwight J. Rouse
12  Departments of Obstetrics and Gynecology, Brown University, Providence, Rhode Island
,
Yasser Y. El-Sayed
13  Departments of Obstetrics and Gynecology, Stanford University, Stanford, California
,
Yoram Sorokin
14  Departments of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
,
Steve N. Caritis
15  Departments of Obstetrics and Gynecology, University of Pittsburgh, Pittsburgh, Pennsylvania
,
for the Eunice Kennedy Shriver National Institute of Child Health Human Development Maternal-Fetal Medicine Units (MFMU) Network› Author Affiliations
Funding This work is supported by grants HD34208, HD53097, HD40545, HD40560, HD27869, HD40485, HD40512, HD27915, HD40544, HD40500, HD68282, HD68268, HD27917, HD21410, and U10 HD36801 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and by funding from Neoventa Medical. Comments and views expressed in this article are those of the authors and do not necessarily represent views of the NICHD. Neoventa Medical did not participate in the monitoring of the study; data collection, management, or analysis; or manuscript preparation.

Abstract

Objective This study aimed to evaluate whether intrapartum fetal electrocardiogram (ECG) tracings with ST-elevation or depression occur more frequently in each stage of labor in small-for-gestational age (SGA) or large-for-gestational age (LGA), as compared with appropriate-for-gestational age (AGA) fetuses.

Study Design We conducted a secondary analysis of a large, multicenter trial in which laboring patients underwent fetal ECG waveform-analysis. We excluded participants with diabetes mellitus and major fetal anomalies. Birth weight was categorized as SGA (<10th percentile), LGA (>90th percentile), or AGA (10–90th percentile) by using a gender and race/ethnicity specific nomogram. In adjusted analyses, the frequency of ECG tracings with ST-depression or ST-elevation without depression was compared according to birthweight categories and labor stage.

Results Our study included 4,971 laboring patients in the first stage and 4,074 in the second stage. During the first stage of labor, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (6.7 vs. 5.5%; adjusted odds ratio [aOR]: 1.41, 95% confidence interval [CI]: 0.93–2.13), or in ST-elevation without depression (35.8 vs. 34.1%; aOR: 1.17, 95% CI: 0.94–1.46). During the second stage, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (1.6 vs. 2.0%; aOR: 0.69, 95% CI: 0.27–1.73), or in ST-elevation without depression (16.2 vs. 18.1%; aOR: 0.90, 95% CI: 0.67–1.22). During the first stage of labor, there were no differences in the frequency of ST-depression in LGA fetuses compared with AGA fetuses (6.3 vs. 5.5%; aOR: 0.97, 95% CI: 0.60–1.57), or in ST-elevation without depression (33.1 vs. 34.1%; aOR: 0.80, 95% CI: 0.62–1.03); during the second stage of labor, the frequency of ST-depression in LGA compared with AGA fetuses (2.5 vs. 2.0%, aOR: 1.36, 95% CI: 0.61–3.03), and in ST-elevation without depression (15.5 vs. 18.1%; aOR: 0.83, 95% CI: 0.58–1.18) were similar as well.

Conclusion The frequency of intrapartum fetal ECG tracings with ST-events is similar among SGA, AGA, and LGA fetuses.

Key Points

  • SGA and LGA neonates are at increased risk of cardiac dysfunction.

  • Fetal ECG has been used to evaluate fetal response to hypoxia.

  • Fetal ST-elevation and ST-depression occur during hypoxia.

  • Frequency of intrapartum ST-events is similar among SGA, AGA and LGA fetuses.

* See [Supplementary Material] for a list of other members of the NICHD MFMU Network.


Supplementary Material



Publication History

Received: 20 February 2021

Accepted: 23 July 2021

Publication Date:
31 August 2021 (online)

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