Cardiotocography (CTG)

Cardiotocography is the method used to assess the uterine contractions and it also measures baby’s heart rate during the pregnancy period. It is usually represented in graph format and is advised in the last trimester. It is usually a non-painful test and the duration of the test may last from 20-60 minutes depending on the condition of the patient.

Cardiotocography reading is taken to know the supply of placental oxygen to the baby during the uterine contraction period, if left unnoticed, may cause an emergency situation, at the time of birth.

CTG baby monitoring involves 2 methods:

External CTG

It is done by placing 2 transducers on the mother’s abdomen to monitor mother’s contractions. The first transducer is placed above the foetal heart and the other near the fundus of the uterus and the graph is noted by the machine. It marks both the beginning and end of the contractions, but the strength and exact time of the contradictions are missed. The main drawback in this method is, it cannot be performed in obese females

Internal CTG

As the name implies, here cardiotocography reading is taken internally from the cervix reaching the scalp of the baby directly to the monitor. It is the very accurate method to monitor a mother’s contraction and the heartbeat of the baby. It gives the exact time and strength of uterine contraction.

Indications of CTG

CTG is indicated when
  • Patient complains of decreased foetal movements.
  • When there is decreased amniotic liquid.
  • In case of twin pregnancy.
  • In medical conditions like diabetes and hypertension.
  • In undue pregnancies.
  • When the fetal growth is reduced or fetal weight is less than normal.

Assessment of CTG Graph

The graph is usually accessed by the health care specialist but although the normal values shows less than or equal to 5 contractions in 10 minutes and the fetal heart rate should be approximately 5 beats in 10 seconds which are considered as normal ie 110-160 beats per minute.


The pregnancy heartbeat monitor helps in diagnosing the complications such as compression of fetal head, placental insufficiency, fetal distress, umbilical cord compression due to the uterine contractions which leads to the variations in the fetal heartbeat. This variations are the result of affected placental oxygen supply during contraction which gives the indication for the emergency caesarean section avoiding many death risks during the delivery period.