Contractions

Synonyms in a broader sense

Induction of labor, labor pains, premature labor.

Definition

Contractions are the basis of birth. The contraction of the muscle layer of the uterus (= the myometrium) generates expulsive forces which have an influence on the cervix and the position of the baby in the pelvic floor. During pregnancy, various types of contractions occur, which increase in strength, frequency and duration until birth and with which the uterus prepares for birth.

Diagnostics

The mother’s statements about back pain, menstrual pain or a feeling of pressure are in the foreground. On the one hand, there is the possibility to visualize the contractions by means of a cardiotocogram (CTG) and to observe the heart rate of the unborn child at the same time. On the other hand, the contractions can be controlled by palpating the abdomen with the hands.

The effectiveness of the contractions can only be confirmed by palpation of the cervix or cervical length measurement in ultrasound. CTG is the abbreviation of cardiotocography, also known as cardiac tone contractions. It simultaneously records the child’s heartbeat as a pulse curve (cardiogram) and the contractions (tocogram).

The heart activity is always shown on the upper curve and the uterine contractions on the lower curve. In this way, the variability of the child’s heartbeat and the immediate reaction of the child to the contractions can be shown, but also the strength and duration of the contractions can be tracked. In addition, child movements can be recorded in the CTG in the form of small horizontal bars.

The child’s heart activity is registered by means of a special ultrasound form, the so-called Doppler sonography. The contractions are recorded via pressure gauges placed on the abdomen of the pregnant woman. Cardiotocography is used for antenatal examinations as well as immediately before and during birth. During childbirth, special attention is paid to the reactions of the child’s heartbeat to the contractions, in order to be able to determine at an early stage any possible danger to the child due to a stress reaction and possible oxygen deficiency, and to be able to react appropriately by obstetrics. So-called late decelerations are particularly feared, which means that the child’s heart rate drops directly after a contraction and indicates a lack of oxygen.