The Resting Cardiotocography (CTG) or Nonstress Test is the method of monitoring pregnancy, by recording uterine contractions and foetal heart rate. Cardiotocography is performed with a specialized machine, the cardiotocograph, to which two transmitters are connected, one for recording contractions and one for recording the heart rate.
The result of the recording is printed on millimetre paper, as well as the cardiogram. From the study of the cardiotocogram we collect data for the normal development of the pregnancy, both for the existence and assessment of any uterine contractions as well as for the normal perspiration and oxygenation of the foetus.
It is performed as a routine method from the 34th week of pregnancy and every week from the 36th week. As a method of monitoring childbirth, the Stress Test is distinguished in abdominal and vaginal:
- The Abdominal (CTG) is performed from the abdomen, where the transmitters are fastened with elastic straps.
- The vagina is used by some maternity hospitals after the rupture of the foetal membranes, where an electrode is placed through the vagina into the scalp of the foetus and provides a more reliable record of foetal heart rate.
By recording the evidence of uterine contractions and foetal heart function, we can assess the normal development of pregnancy or childbirth, as well as the pathological conditions where we need to intervene.