ABSTRACT Background: International guidelines on management of preeclampsia differ in various aspects including recommendations with regard to frequency of maternal blood tests and proteinuria quantification ante- and postpartum. Norwegian guidelines do not problematize frequency of these surveillance parameters (1-3). Clinical presentation, severity and progression of the disease will influence the clinicians’ evaluation of the need for repeated testing. However, especially in the immediate postpartum period, when maternal hemodynamic changes influence circulating levels of for example liver enzymes, frequency of preeclampsia panels of blood tests could probably be restricted. Methods: We conducted an observational study, with prospective assessment of antepartum and postpartum maternal blood testing and proteinuria quantification in women hospitalized due to preeclampsia. The observational period was 75 days in total. Health-economic costs were estimated based on actual laboratory costs from the Department of Medical Biochemistry, Oslo University Hospital (OUH). A review of both international and national clinical guidelines on preeclampsia surveillance was conducted by accessing publications of the respective organizations. Results: Out of 8 national guidelines and 2 international guidelines, only one contained explicit recommendations for antepartum and postpartum maternal blood testing and proteinuria quantification regarding frequency and different panels of blood tests. During the observational period, 42 women admitted for preeclampsia were included, yielding 430 blood tests in total. We registered 68 different panels of biochemical parameters. Of these, 38 included total platelet count, liver enzymes and serum creatinine. We found a health economical difference in costs of 56 680 NOK, comparing actual costs with recommendation of National Institute for Health and Care Excellence guideline. Conclusion: We observed a wide variety of practice regarding blood tests, both with regard to frequency of repeated testing and to biochemical parameters included. Differences in presentation and clinical course of preeclampsia will justify an individualized surveillance of biochemical parameters. However, especially in the immediate postpartum period, the usefulness of extensive repeated testing can be questioned both with regard to the individual burden for the affected women as well as to health-economics considerations.