Cardiotocography in preterm birth

Premature birth is a public health problem worldwide. Due to the lack of cardiotocography (CTG) guidelines in preterm infants according to different gestational ages, we analyzed literature and synthesized the physiological and pathological characteristics of the CTG route of different gestational age preterm infants. The purpose of this analysis is to summarize the most relevant information regarding CTG monitoring in pregnancies with preterm infants and to provide CTG follow-up criteria for the daily practice of these conditions. In conclusion, the baseline of the fetal heart rate it is slightly increased in premature fetuses and decreases with increasing gestational age. During the second trimester of pregnancy, low-amplitude transitory decelerations occur more frequently and with a much lower frequency by the end of the third trimester. Cycling of variability is reduced due to incomplete development of the parasympathetic component of the autonomic nervous system in premature fetuses.