An observational study in High Risk Pregnancy, Congenital Heart Disease and Fetal Hydrops, sponsored by Medical College of Wisconsin. Recruiting at 2 sites in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-04.
Sponsored by Medical College of Wisconsin · Observational
Each year world-wide, 2.5 million fetuses die unexpectedly in the last half of pregnancy, 25,000 in the United States, making fetal demise ten-times more common than Sudden Infant Death Syndrome. This study will apply a novel type of non-invasive monitoring, called fetal magnetocardiography (fMCG) used thus far to successfully evaluate fetal arrhythmias, in order to discover potential hidden electrophysiologic abnormalities that could lead to fetal demise in five high-risk pregnancy conditions associated with fetal demise.
Fetal demise occurs in over 25,000 pregnancies annually in the US and over 2.5 million in pregnancies worldwide. Certain maternal-fetal-placental abnormalities can have a high risk of fetal demise. Despite advances in fetal surveillance with ultrasound and cardiotocography, the reduction in fetal mortality lags behind that of the neonate and has shown little decline in the past decade. This suggests that the type of fetal monitoring used may not be assessing the correct indicators of mortality. In all other age groups, electrocardiographic (ECG) and continuous heart rate (HR) monitoring are used in every intensive care unit or emergency setting; however, for the fetus, the ECG signal is nearly completely insulated and inaccessible. As the result, indirect assessment of cardiac rhythm is obtained using echocardiography/Doppler, but echo/Doppler does not have the precision to assess beat-to-beat HR variability and cannot assess cardiac repolarization at all. In this study, the investigators will evaluate five high risk conditions (major congenital heart disease in the fetus, fetal hydrops (immune and non-immune), monochorionic twin pregnancy, prior pregnancy ending in fetal demise, and gastroschisis) using Fetal Magnetocardiography (fMCG)which detects the natural magnetic signals accompanying the cardiac electrical signal. It is a new, safe, and non-invasive recording technique that has been performed for several decades, and has recently gained FDA approval for recording cardiac signals at all ages, including in the fetus. Normative data has been obtained at the University of Wisconsin - Madison Biomagnetism Laboratory in 257 healthy fetuses by co-investigator Ronald T. Wakai, PhD. Over 550 serious fetal arrhythmias have been evaluated to date. Fetal MCG has proven invaluable in fetal Long QT Syndrome in identifying markers for risk of sudden death such as Torsades de Pointes Ventricular Tachycardia (VT), T wave alternans, 2nd degree AV block, and QTc>590 ms. To date, fMCG has not been systematically applied to diseases that are not associated with recognizable arrhythmias because the impact of silent conduction and repolarization defects has been underappreciated. In this grant, the investigators hypothesize that beat-to-beat fetal heart rate variability abnormalities and electrophysiologic abnormalities, are present in five high risk maternal-fetal-placental conditions associated with fetal demise. The study will determine which electrophysiologic abnormalities precede fetal demise or adverse pregnancy outcome. Preliminary findings in healthy normal subjects in RO1HL063174 (Wakai) show repolarization abnormalities in up to 5%, and some of these are modifiable once recognized. Two hundred pregnant subjects will be studied over a 5 year period both at referral (\~20-27 weeks GA) and later in pregnancy at 30-37 weeks GA. fMCG results will be compared to neonatal ECG (nECG) obtained at 0-4 weeks of life. This will determine whether specific abnormal heart rate, rhythm and conduction patterns emerge that characterize the condition, which will then allow the high risk obstetrician to better predict risk of fetal demise in the future.
101 studies on the registry are indexed under Long QT Syndrome; 20 are open to participants now.
This study's planned enrollment of 30 is below the median of 150 across 53 observational studies indexed under Long QT Syndrome.
Browse Long QT Syndrome studies →Medical College of Wisconsin is the lead sponsor of 548 studies on the registry; 122 are open to participants now.
Of its 75 completed or terminated interventional studies of FDA-regulated products, 57 (76%) have results posted.
Compared within Long QT Syndrome, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Heart Defects, Congenital. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Current pregnancy complicated by one of the five diagnostic categories (fetal major congenital heart disease, prior unexplained Stillbirth at/after 20 weeks gestation, fetal hydrops, fetal gastroschesis, or monochorionic twin pregnancy.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Current pregnancy complicated by one of the five diagnostic categories
Exclusion Criteria:
An electric stimulation device (TENS unit, pacemaker, or nerve stimulator) that could produce electric or magnetic noise.
The subject will have a single 2-3 hour fetal magnetocardiogram at approximately 20 and 27 weeks GA, and again, if medical condition allows, between 30 and 37 weeks GA, then her infant will have an between 0 and 4 weeks of age. Subjects will be paid a nominal fee for their participation each time, as well as transportation reimbursement if >25 miles. For subjects traveling a long distance, the ECG may be performed locally or at home.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Pregnancy with major fetal congenital heart disease, after 20 weeks gestation, and as neonate following delivery. Two fetal magnetocardiograms (fMCG) and 1 neonatal electrocardiogram (nECG) will be obtained and heart rate, rhythm, and conduction patterns will be compared.
Diagnostic Test: Fetal Magnetocardiogram and Neonatal Electrocardiogram
Pregnancy with a history of an unexplained fetal demise (stillbirth at 20 -40 weeks gestation) during any prior pregnancy. Two fetal magnetocardiograms (fMCG) and 1 neonatal electrocardiogram (nECG) will be obtained and heart rate, rhythm, and conduction patterns will be compared.
Diagnostic Test: Fetal Magnetocardiogram and Neonatal Electrocardiogram
Pregnancy with fetal hydrops, immune or non-immune, at or after 20 weeks gestation. Two fetal magnetocardiograms (fMCG) and 1 neonatal electrocardiogram (nECG) will be obtained and heart rate, rhythm, and conduction patterns will be compared.
Diagnostic Test: Fetal Magnetocardiogram and Neonatal Electrocardiogram
Pregnancy with fetal gastroschisis, at or after 20 weeks gestation. Two fetal magnetocardiograms (fMCG) and 1 neonatal electrocardiogram (nECG) will be obtained and heart rate, rhythm, and conduction patterns will be compared.
Diagnostic Test: Fetal Magnetocardiogram and Neonatal Electrocardiogram
Twin pregnancy, monochorionic, with or without twin-twin transfusion syndrome, at or after 20 weeks gestation. Two fetal magnetocardiograms (fMCG) and 1 neonatal electrocardiogram (fMCG) will be obtained and heart rate, rhythm, and conduction patterns will be compared.
Diagnostic Test: Fetal Magnetocardiogram and Neonatal Electrocardiogram
Mothers who are taking medications that impact QT interval, and/or are used to treat either a maternal risk of arrhythmi (Inherited arrhythmia Syndromes) or used for fetal tachycardia management are eligible for the substudy evaluating maternal and infant pharmacogenomics. PG will be measured after delivery by RPRD, Inc with results conveyed to the subject by the PI. The results are not used for clinical management of the pregnancy.
Genetic: Substudy only: Maternal/Infant Pharmacogenomic assessment postnatally
Fetal Magnetocardiography (fMCG) is a new non-invasive diagnostic procedure that records tiny fetal cardiac signals similar to an Electrocardiogram or Holter monitor. The magnetometer has FDA clearance, and does not emit magnetic, electric or other energies. This is not an MRI. Examples of fetal MCG's can be found in the Links. The American Heart Association Scientific Statement on Fetal Diagnosis and Treatment (Circulation, 2014) has declared fMCG to be Class IIa for fetal heart rhythm abnormalities, meaning that benefit far exceeds risk. As part of this study, a neonatal electrocardiogram (nECG) will be obtained for comparison after the baby is born.
See also section 6. Pharmacogenomics measure the way the liver breaks down medications. The systems controlling this are inherited, and mothers or infants can be normal, fast, ultrafast, or poor metabolizers for certain drugs. This study will attempt to improve future safety of cardiac drug treatments for both mother and fetus by evaluating the impact of PG.
Heart rate variability using fMCG
To measure and compare the fMCG heart rate variability in five pregnancy conditions associated with fetal demise, to those of gestation matched normal fetuses.
Time frame: Comparison of procedures at approximately 20-27 weeks gestation, at 30-37 weeks gestation, and at neonatal ECG at 0-4 weeks of age
Cardiac conduction
To measure and compare the fMCG cardiac time intervals in five pregnancy conditions associated with fetal demise, to those of gestation matched normal fetuses and to neonatal ECGs at 0-4 weeks of age.
Time frame: Comparison of cardiac time intervals at approximately 20-27 weeks gestation, 30-37 weeks gestation and at neonatal ECG at 0-4 weeks of age
Cardiac repolarization
To measure and compare the fMCG cardiac repolarization patterns in five pregnancy conditions associated with fetal demise, to those of gestation matched normal fetuses, and to neonatal ECGs at 0-4 weeks of age.
Time frame: Comparison of cardiac repolarization at approximately 20-27 weeks gestation, 30-37 weeks gestation and neonatal ECG at 0-4 weeks of age.
Unique "signature" electrophysiologic abnormalities
2a) To determine whether unique "signature" electrophysiologic abnormalities are present in any of these five maternal-fetal diseases, and 2b) to define at what trimester these develop. Understanding any unique findings could allow study of specific treatment strategies in the future. findings are first seen.
Time frame: Comparison of findings at approximately 20-27 weeks gestation, 30-37 weeks gestation and neonatal ECG at 0-4 weeks of age
Pregnancy outcomes
To correlate fMCG findings with 3a) outcomes of pregnancies (fetal demise, premature delivery, small for GA, 5 minute APGAR \< 5, neonatal death) and 3b) fMCG cardiac time intervals with postnatal ECG intervals at 0-4 weeks of age.
Time frame: Comparison of findings at approximately 20-27 weeks gestation, 30-37 weeks gestation and neonatal ECG at 0-4 weeks of age
Plan to share: No — Only de-identified data can be released
Started Jul 2018 (actual). Primary completion is estimated for Nov 2028, 124 months after the start.
Of 21 observational studies under Long QT Syndrome, half reached primary completion within 56 months of starting (the median), counting those still running; a quarter within 26 and three quarters within 81. This study's planned 124 months is above that.
How these figures are worked out, and which studies are left out of them.
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