Fetal heart sounds were described as early as 350 years ago and approximately 200 years ago mechanical stethoscopes, such as the Pinard horn, were introduced in clinical practice.
Modern-day CTG was developed and introduced in the 1950s and early 1960s by Edward Hon, Roberto Caldeyro-Barcia and Konrad Hammacher. The first commercial fetal monitor (Hewlett-Packard 8020A) was released in 1968.[1]
CTG monitoring is widely used to assess fetal well-being by identifying babies at risk of hypoxia (lack of oxygen).[2] CTG is mainly used during labour.[3][4] A review found that in the antenatal period (before labour), there is no evidence to suggest that monitoring women with high-risk pregnancies benefits the mother or baby, although research around this is old and should be interpreted with caution.[5] Up-to-date research is needed to provide more information surrounding this practice.[5]
A study found that CTG monitoring didn't significantly improve or worsen the outcome, in terms of preventable child death, post birth mortality, of pregnancy for high risk mothers. But the evidence examined in the study is quite old and there have been significant changes in medical care since then.[5]