The importance of antepartum cardiotocography

The significance of antepartum cardiotocography was examined on patients at the University of Cologne in the years 1982 and 1983. We analyzed 13,310 cardiotocograms of 1,463 women and correlated their pregnancies and deliveries with the status of their newborns. There were only 66 suspect/prepathologic fetal heart rate recordings in 50 patients. All these patients had severe complications during their pregnancies. Impending prematurity, toxemia, first and second trimester bleeding as well as placental insufficiency and polyhydramnios were the leading complications. The analysis of the cardiotocograms using Hammacher's criteria demonstrated that the CTG characteristics "floating line" and "oscillation type" together accounted for the largest proportion (43.9%) to the total score and thus constituted the most important parameters. Fetuses with abnormal CTGs had a birthweight of less than 1500 grams in 30% of the cases. This group also had poorer Apgar scores and umbilical artery pH values than neonates with normal antepartum cardiotocograms. After excluding non-viable malformations the perinatal mortality was 80 per 1000, i.e. it was nine times higher for newborns with abnormal antepartum heart rate patterns. The study demonstrated that abnormal antepartum CTGs in non-selected patients are rare and are always associated with severe complications of pregnancy. Thus, the method is not suitable as a general screening method but should be used for specific indications in high risk pregnancies and for the evaluation of any tocolytic treatment. The recognition of abnormal CTG characteristics requires technically adequate recording and accurate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)