Standard External Doppler Fetal Heart Tracings versus External Fetal Electrocardiogram in Very Preterm Gestation: A Pilot Study.
IntroductionVery preterm babies can be difficult to monitor using standard external Doppler fetal heart tracings (eFHR). External fetal electrocardiogram (fECG) is a potential alternative.MethodsThis was a prospective observational pilot study of hospitalized patients at 24 to 28 weeks' gestation. A total of 30 women were traced for up to 2 hours using eFHR followed by up to 2 hours using fECG. The percentage of time the fetal heart rate was traced during the 2-hour window for each modality was calculated. Differences of ≥ 60, ≥ 80, and ≥ 90% total time traced were compared between modalities using McNemar's test. Differences were also assessed for each method between nonobese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) women using chi-square and Fisher's exact tests.ResultsSuperior performance was found with eFHR at ≥ 60% (93.3 vs. 46.7%,p< 0.001), ≥ 80% (80.0 vs. 30.0%,p< 0.001), and ≥ 90% (60.0 vs. 23.3%,p< 0.01) total time traced. There was a statistically significant finding favoring nonobese women at ≥ 80% total time traced using fECG (7.1 vs. 50.0%,p= 0.017).ConclusionWith current technology fECG performance in very preterm gestation was worse than conventional eFHR, although fECG may have a role in nonobese patients.
Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology, and Women's Health, Saint Louis University School of Medicine, Saint Louis, Missouri.
Gary
G
Fruhman
Division of Research, Department of Obstetrics, Gynecology, and Women's Health, Saint Louis University School of Medicine, Saint Louis, Missouri.
Jeffrey A
JA
Gavard
Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology, and Women's Health, Saint Louis University School of Medicine, Saint Louis, Missouri.
Kristina
K
McCormick
SSM Health-Saint Mary's Hospital, Saint Louis, Missouri.
Judy
J
Wilson-Griffin
Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology, and Women's Health, Saint Louis University School of Medicine, Saint Louis, Missouri.
Erol
E
Amon
Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology, and Women's Health, Saint Louis University School of Medicine, Saint Louis, Missouri.
Gilad A
GA
Gross
external heart rate tracing; fetal ECG; obesity; preterm