Jan Degenhardt

Dr. Jan Degenhardt

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 August 2022 in Journal of Clinical Medicine
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Ivonne BedeiIvonne Bedei
Ivonne Bedei
AGAlexander Graf
Alexander Graf
KGKarl-Philipp Gloning
Karl-Philipp Gloning
MMMatthias Meyer-Wittkopf
Matthias Meyer-Wittkopf
DWDaria Willner
Daria Willner
RARoland Axt-Fliedner
Roland Axt-Fliedner
Mirror syndrome is a rare and serious maternal condition associated with immune and non-immune fetal hydrops after 16 weeks of gestational age. Subjacent conditions associated with fetal hydrops may carry different risks for Mirror syndrome. Fetuses with Turner syndrome are frequently found to be hydropic on ultrasound. We designed a retrospective multicenter study to evaluate the risk for Mirror syndrome among pregnancies complicated with Turner syndrome and fetal hydrops. Data were extracted from a questionnaire sent to specialists in maternal fetal medicine in Germany. Out of 758 cases, 138 fulfilled our inclusion criteria and were included in the analysis. Of the included 138, 66 presented with persisting hydrops at or after 16 weeks. The frequency of placental hydrops/placentomegaly was rather low (8.1%). Of note, no Mirror syndrome was observed in our study cohort. We propose that the risk of this pregnancy complication varies according to the subjacent cause of fetal hydrops. In Turner syndrome, the risk for Mirror syndrome is lower than that reported in the literature. Our observations are relevant for clinical management and parental counseling.

2 September 2015 in Ultraschall in der Medizin - European Journal of Ultrasound
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JDJan Degenhardt
Jan Degenhardt
MRMeike Reinold
Meike Reinold
CEChristian Enzensberger
Christian Enzensberger
AWAline Wolter
Aline Wolter
AKAndrea Kawecki
Andrea Kawecki
RARoland Axt-Fliedner
Roland Axt-Fliedner
Purpose To evaluate pre- and post-procedure myocardial function in monochorionic twins with TTTS who underwent laser ablation of placental anastomoses using pulsed wave tissue Doppler imaging (pw TDI). Materials and Methods 20 monochorionic twin gestations with TTTS were included and underwent laser ablation at our center between 2011 and 2014. Prior to and after the intervention, cardiac function was assessed by measuring the mitral annular plane systolic excursion (MAPSE), the tricuspid annular plane systolic excursion (TAPSE), Tei index, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) for the left ventricle in pulsed wave Doppler (pw D) ultrasound as well as ICT, ET, IRT and Tei index in pw TDI for the left and right ventricle. E-, A-, E´- and A´-wave peak velocity and the systolic downward motion (S´) were measured for both ventricles and the E/A, E/E´ and E´/A´ ratios were calculated. In a mean of 1.3 (SD 0.6) days after laser ablation, this measurement protocol was repeated. Results Pre-intervention recipients had longer ICT, ET and IRT in pw D and pw TDI compared to donors not reaching statistical significance for most parameters. Statistically significant were prolonged ICT in pw D (p 0.01) and ET (p 0.01) in pw TDI in recipients. In donor fetuses preoperative myocardial function did not differ significantly from postoperative myocardial function except in increased left ventricular ejection time of the left ventricle in pw TDI (p 0.04) and an increased E´/A´ratio (p 0.01). After laser coagulation, myocardial function was slightly altered in recipients as ICT and IRT shortened and Tei indices decreased but only reaching statistical significance in shortened IRTs in pw TDI for both ventricles. Conclusion Laser ablation of placental anastomoses in TTTS might influence myocardial function in the postoperative period. Shortened IRT intervals may reflect an improvement of diastolic function in recipients.

1 October 2015 in Ultraschall in der Medizin - European Journal of Ultrasound
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AWAline Wolter
Aline Wolter
AKAndrea Kawecki
Andrea Kawecki
RSRüdiger Stressig
Rüdiger Stressig
JRJochen Ritgen
Jochen Ritgen
JDJan Degenhardt
Jan Degenhardt
RARoland Axt-Fliedner
Roland Axt-Fliedner
Purpose The purpose of this study was to assess the cardiac axis in fetuses with conotruncal anomalies during four-chamber view scanning. Materials and Methods We retrospectively evaluated the cardiac axis of 150 fetuses with conotruncal anomalies within the second and third trimester between October 2008 and August 2014. The cardiac axis was obtained by the angle of two lines in a transverse view of the fetal thorax at the level of the four-chamber view. The first line divided the thorax into two equal halves starting from the spine posteriorly ending at the sternum. The second line was placed through the interventricular septum of the fetal heart. The angle was calculated using OsiriX software. Results 23 had double outlet right ventricle (DORV), 17 had truncus arteriosus communis (TAC), 36 had tetralogy of Fallot (TOF), and 74 had complete transposition of the great arteries (d-TGA). In fetuses with DORV ≤ 24 + 6 weeks of gestation (wks), the mean cardiac axis was 52.5° (p = 0.005), at ≥ 25 + 0 wks it was 51.1° (p = 0.0003). In fetuses with TAC ≤ 24 + 6 wks, the mean cardiac axis was 56.8° (p = 0.01), at ≥ 25 + 0 wks it was 50.0° (p = 0.05). In fetuses with TOF ≤ 24 + 6 wks, the mean cardiac axis was 67.5° (p < 0.0001), at ≥ 25 + 0 wks it was 63.8° (p < 0.0001). In fetuses with d-TGA ≤ 24 + 6 wks, the mean cardiac axis was 45.6°, at ≥ 25 + 0 wks it was 45.4° (not significant). Throughout gestation, the cardiac axis did not show a difference in the two separate examinations. Conclusion In fetuses with DORV, TAC and TOF, the cardiac axis is significantly different from the normal axis, but in fetuses with TGA there is no significant difference compared to the normal axis. Therefore, analysis of the heart axis could be useful for screening for conotruncal anomalies. Ziel Bestimmung der fetalen Herzachse im Vierkammerblick bei Feten mit konotrunkalen Anomalien. Material und Methoden Retrospektive Analyse von 150 Feten mit konotrunkalen Anomalien im zweiten und dritten Trimenon im Zeitraum von Oktober 2008-August 2014. Die Herzachse wurde bestimmt als Winkel zwischen einer Medianlinie durch den Thorax von der Wirbelsäule bis zum Sternum sowie einer zweiten Linie entlang der kardialen Achse durch das Ventrikelseptum. Die Winkelberechnungen erfolgten mittels OsiriX-Software. Ergebnisse 23 Feten mit Double Outlet Right Ventricle (DORV), 17 mit Truncus arteriosus communis (TAC), 36 mit Fallot-Tetralogie (TOF) und 74 mit Transposition der großen Arterien (d-TGA) wurden untersucht. Bei Feten mit DORV vor 24 + 6 Schwangerschaftswochen (SSW) betrug die Herzachse im Mittel 52,5° (p = 0,005), und nach 25 + 0 SSW 51,1° (p = 0,0003). Bei Feten mit TAC vor 24 + 6 SSW betrug die Herzachse im Mittel 56,8° (p = 0,01) und nach 25 + 0 SSW 50,0° (p = 0,05). Bei Feten mit TOF vor 24 + 6 SSW betrug die Achse im Mittel 67,5° (p < 0,0001), danach 63,8° (p < 0,0001). Bei Feten mit d-TGA vor 24 + 6 SSW betrug die Achse im Mittel 45,6°, nach 25 + 0 SSW 45,4° (nicht signifikant). Im Schwangerschaftsverlauf zeigten sich keine Veränderungen der Herzachse der untersuchten Feten. Schlussfolgerung Bei Feten mit DORV, TAC und TOF weicht die fetale Herzachse signifikant von der normalen Herzachse ab. Bei Feten mit d-TGA zeigte sich keine Veränderung. Die Analyse der fetalen Herzachse könnte als Screening-Instrument für konotrunkale Anomalien in der Basisuntersuchung des Herzens sinnvoll sein.

Verified
Journal Article
Open access
PDF file
ABArne Bergsch
Arne Bergsch
JDJan Degenhardt
Jan Degenhardt
RSRüdiger Stressig
Rüdiger Stressig
HDHeiko Dudwiesus
Heiko Dudwiesus
Oliver  GraupnerOliver Graupner
Oliver Graupner
JRJochen Ritgen
Jochen Ritgen
Background: This study assesses the effects of the ‘Radiant’ image enhancement technique on fetal nuchal translucency (NT) measurements during first-trimester sonographic exams. Methods: A retrospective analysis of 263 ultrasound images of first-trimester midsagittal sections was conducted. NT measurements were obtained using a semi-automatic tool. Statistical methods were applied to compare NT measurements with and without ‘Radiant’ enhancement. An in vitro setup with predefined line distances provided additional data. Results: Incremental increases in NT measurements were observed with varying levels of ‘Radiant’ application: an average increase of 0.19 mm with ‘Radiant min’, 0.24 mm with ‘Radiant mid’, and 0.30 mm with ‘Radiant max.’ The in vitro results supported these findings, showing consistent effects on line thickness and measurement accuracy, with the smallest mean deviation occurring at the ‘Radiant mid’ setting. Conclusions: ‘Radiant’ image enhancement leads to significant increases in NT measurements. To avoid systematic biases in clinical assessments, it is advisable to disable ‘Radiant’ during NT measurement procedures. Further studies are necessary to corroborate these findings and to consider updates to the NT reference tables based on this technology.

11 August 2025 in Preprints.org
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PKPhilipp Kreiselmaier
Philipp Kreiselmaier
MPMakis Papadopolous
Makis Papadopolous
JRJochen Ritgen
Jochen Ritgen
JDJan Degenhardt
Jan Degenhardt
Background/Objectives: Nuchal translucency (NT) measurement is an established first-trimester screening tool for chromosomal abnormalities. However, standardized risk assessment models are only validated for fetuses with a crown-rump length (CRL) between 45 and 84 mm. This study investigates the clinical significance of increased NT in fetuses with a CRL between 35 and 45 mm. Methods: This retrospective study analyzed 208 singleton pregnancies with a CRL <; 45 mm and an NT ≥ 2.5 mm, examined at two tertiary prenatal centers between 2008 and 2024. Data on chromosomal findings, structural anomalies, and pregnancy outcomes were collected through follow-up. Statistical analyses included univariate, bivariate, and ROC curve analysis to determine optimal NT cut-off values for predicting adverse outcomes. Results: Chromosomal abnormalities were present in 67/208 cases (32.2%), with trisomy 18 being the most frequent. Malformations were detected in 46.7% of cases with available follow-up. The optimal NT cut-off for predicting an abnormal karyotype was 3.89 mm (sensitivity 79.1%, specificity 55.3%). Among fetuses with NT ≥ 5.5 mm, the rate of adverse outcomes reached 83.7%. Notably, 29.9% of chromosomal abnormalities would not have been detected by NIPT alone. Overall, the presence of increased NT—even below the standard CRL threshold—was associated with a significantly elevated risk of genetic and structural abnormalities as well as adverse pregnancy outcomes. Conclusions: NT measurement in fetuses with CRL < 45 mm provides clinically relevant prognostic information. Elevated NT in this early gestational window is significantly associated with chromosomal anomalies, structural defects, and poor pregnancy outcomes. Reliance on NIPT alone in this cohort may miss a substantial proportion of abnormal cases. Early NT assessment should prompt comprehensive diagnostic evaluation and genetic counseling, even when CRL is below 45 mm.

13 May 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
ABArne Bergsch
Arne Bergsch
JDJan Degenhardt
Jan Degenhardt
RSRüdiger Stressig
Rüdiger Stressig
HDHeiko Dudwiesus
Heiko Dudwiesus
OGOliver Graupner
Oliver Graupner
JRJochen Ritgen
Jochen Ritgen
Background: This study assesses the effects of the ‘Radiant’ image enhancement technique on fetal nuchal translucency (NT) measurements during first trimester sonographic ex-ams. Methods: A retrospective analysis of 263 ultrasound images of first trimester midsagittal sections was conducted. NT measurements were obtained using a semi-automatic tool. Statistical methods were applied to compare NT measurements with and without ‘Radi-ant’ enhancement. An in-vitro setup with predefined line distances provided additional data. Results: Incremental increases in NT measurements were observed with varying levels of ‘Radiant’ application: An average increase of 0.19 mm with ‘Radiant min’, 0.24 mm with ‘Radiant mid’ and 0.30 mm with ‘Radiant max.’ The in-vitro results supported these findings, showing consistent effects on line thickness and measurement accuracy, with the smallest mean deviation occurring at the ‘Radiant mid’ setting. Conclusions: ‘Radiant’ image enhancement leads to significant increases in NT measure-ments. To avoid systematic biases in clinical assessments, it is advisable to disable ‘Radi-ant’ during NT measurement procedures. Further studies are necessary to corroborate these findings and to consider updates to the NT reference tables based on this technology.