Inclusion Criteria:

- Offered patient information and written informed consent

- Female patients aged greater than or equal to 18 years:

1. for reduction of a primary ovarian tumour or recidive of an ovarian tumour

2. pregnant patients with:

- clinical normal pregnancy

- pregnancy with weight gain of more than 10 kg

- pregnancy and gestosis

3. healthy volunteers

Exclusion Criteria:

- Persons without the capacity to consent

- Unability of German language use

- Lacking willingness to save and hand out data within the study

- Accommodation in an institution due to an official or judicial order

- (Unclear) history of alcohol or substances disabuse

- Coworker of the Charité

- Advanced disease of the oesophagus or upper respiratory tract

- Operation in the area of the oesophagus or nasopharynx within the last two months

- Neurological or psychiatric disease

- CHF (congestive heart failure) according to (New York Heart Association)
classification - NYHA class IV at the beginning of hospital stay

- American Society of Anaesthesiologists (ASA) classification greater than IV

- Renal insufficiency (dependency of haemodialysis)

- Pulmonal oedema in thorax x-ray

- History of intracranial hemorrhage within one year of participation in the study

- Conditions following venous thrombosis within the last three years before study
inclusion

- Inflammatory or reflective disease of blood vessels (Raynaud-Syndrome, Vasculitis)

- Inherent connective tissue disease(e.g. Marfan Syndrome)