Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Pohl, M.
Dynamics of Intraabdominal and Intrauterine Pressures During Amnioreduction
Humanmedizin; [ Diplomarbeit ] Medical University of Graz; 2021. pp. 90
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Greimel Patrick
- Schneditz Daniel
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- Abstract:
- Background Continuous uterine pressure recordings outside labour are rare since they require an invasive procedure which is morally difficult to justify. This work presents the findings of continuous uterine and abdominal pressure recordings during therapeutic amnioreductions. Methods Stepwise amnioreduction following the fetoscopic laser ablation (FLA) treatment of a twin-twin transfusion syndrom (TTTS) enabled the measurements of the intrauterine pressure (IUP). Hands off phases, conducted after each step, allowed recordings free from external interferences. Additionally, the placental perfusion pressure (PPP) was derived by non-invasive haemodynamic measurements. Overall, the maternal dynamics of five patients were recorded and four were included in the analysis (n = 4). Results Strong uterine contractions with a maximum intrauterine pressure up to 63.8 mmHg were recorded. Simultaneously, the intraabdominal pressure fell in a number of instances. During uterine contractions the placental perfusion pressure decreased and thereby reduced foetal oxygenation. Respirational pressure changes in the abdominal cavity revealed a pressure transmission of 88 % on the uterus. On average we found the uterine transmural elastance to be 2.8 mmHg/l. Conclusion The fall in intraabdominal pressure during uterine contractions suggests that the observed contractions lower the placental volume to reduce the negative effects of the placental steal phenomenon following amnioreduction. The low placental perfusion pressure levels and the related foetal oxygenation should be further investigated and remembered during amnioreductions to guarantee a stable foetal oxygenation. The high pressure transmission shows that an elevated intraabdominal pressure has a strong effect on the intrauterine pressure and we assume this result applies to all pregnancies. This thesis uncovers some unknown dynamics during amnioreduction which will become more relevant in the future since the number of therapeutic amnioreductions will increase with rising twin pregnancies.