[Intensive fetal monitoring sub partu or the quality of clinical research].

The first prospective randomised study comparing intermittent auscultation of the fetal heart rate with continuous electronic monitoring during labour and delivery, which showed an increased rate of Caesarean sections in the group with electronic monitoring without significant benefit to the newborn, met with great scepticism on the part of many perinatologists. Meanwhile, 8 additional prospective randomised trials confirmed the first results. The debate concerning the benefit and need of fetal monitoring during labour has even generated doubts regarding the need for, and benefit of, prospective randomised studies. Various study designs have been used in clinical research to test new diagnostic and therapeutic methods. Observational studies generally provide first impressions which are then strengthened by comparison of study patients with historical controls from the time before the introduction of the new method. Retrospective or prospective matched pair studies may also support the initial hypothesis. The gold standard of all designs is undoubtedly the prospective randomised trial. A double blind randomisation should be performed if feasible, in which neither the subject concerned nor the investigator are aware as to how the patient has been assigned. Only by a prospective randomised study design, known and unknown variables which may affect the outcome can be controlled and will not interfere with the assessment of the new method, since they will appear in equal measure both in the study and in the control group. In view of the rapid development of the discipline of perinatal medicine, with the evolvement of manifold new diagnostic and therapeutic methods, a critical assessment of these methods using the principle of the prospective randomised study design, is imperative. The clinical investigator has a moral obligation towards the patient to select that method which is of maximum benefit with minimum risk to the patient. In addition, in view of the drastic need for controlling expenditure in health care, it is in the interest of society that the use of methods with questionable benefit or with an unreasonable cost-benefit ratio is avoided by means of critical assessment and selection.