[Significance of various oxytocin challenge tests in monitoring pregnant women at risk (author's transl)].

Three different oxytocin challenge tests were used for the anssessment of placentar function in pregnant women at risk: For the oxytocin test after Ray et al. Oxytocin was given in continuity with rising doses. In the two other tests Oxytocin was given intermittently with identical doses. The test described by Ray et al. Proved useful for predicting respiratory insufficiency of the placenta. The two other intermittent tests are, according to our investigations, less suitable as tests of placentar function because their significance is limited or non-existent. The continuous oxytocin challenge test takes more time (one hour on average). Essential for exact interpretation are a careful technique and surveillance of the patient throughout the test by trained personel. In our opinion the indications for the continous oxytocin challenge test are pregnancies at risk, where antepartum cardniotocography shows suspect or hard-to-interprete results (e.g. non-classifiables decelerations, loss of fluctuation, absence of Braxton-Hicks contractions) or when other monitoring techniques indicate placentar insufficiency (e.g. low oestriol excretion). The test is not suitable in placenta previaprevia, threatened premature birth and premature ruptur of the membranes. In contrast to other authors we cannot decide with certainly whether patients with a positive oxytocin challenge test should in every case be treated with Caesarean section [9]. This decision will depend not only on the result of the test but on the assessment of all parameters, mainly on the clinical picture. In any case delivery of patients with positive oxytocin challenge tests will have to be carried out under strict technical and biochemical supervision.