Second line methods are used to help obstetricians to identify abnormalities that reflect foetal acidosis. Since the use of a new technique of cardiotocography (CTG) interpretation based on the pathophysiology of the foetal period, the use of second-line tests has been questioned.

To evaluate the impact of specific training in CTG physiology-based interpretation on professional attitudes towards the use of second-line methods.

This cross-sectional study included 57 French obstetricians divided into two groups: the trained group (obstetricians who had already participated in a training course in physiology-based interpretation of CTG) and the control group. Ten medical records of patients who had abnormal CTG tracings and underwent foetal blood sampling pH measurement during labour were presented to the participants. They were given three choices: use a second-line method, continue labour without using second-line method, or perform a caesarean section. The main outcome measures was the median number of decisions to use second-line method.

Forty participants were included in the trained group and 17 in the control group. The median number of recourses to second-line method was significantly inferior for the trained group (4/10 s-line methods) than for the control group (6/10, p = 0.040). Regarding the 4 records for which a caesarean section was the real outcome, the median number of decisions of continuing labour was significantly superior in the trained group than in the control group (p = 0.032).

Participation in a training course in physiology-based interpretation of CTG could be associated with a less frequent use of second-line method at the cost of more frequently continuing labour with the risk compromising foetal and maternal well-being. Additional studies are required to determine whether this change in attitude is safe for the foetal well-being.