Rational approach to fetal heart rate monitoring and management during the second stage of labor.

Second stage of labor is considered to be associated with an increased risk of intrapartum fetal hypoxic injury. This is due to a combination of several risk factors such as -the increased frequency, strength and duration of uterine contractions due to higher number and affinity of myometrial oxytocin receptors; -the Ferguson's reflex which leads to a reflex release of endogenous oxytocin in response of the distension of the cervix by descending fetal head in late stages of labor; maternal expulsive efforts with the Valsalva manoeuvre that may reduce maternal oxygenation, as well as reduce the venous return and maternal cardiac output due to increased intrathoracic pressure, winch may lead to reduced placental oxygenation; - and increased fetal intracranial pressure due to head compression leading to a potential decrease in fetal cerebral oxygenation. In addition, the umbilical cord often forms one or more loops around the fetal neck, which may get tightened as the head descends leading to an acute and intermittent cessation of fetal oxygenation.

International expert consensus statement on physiological interpretation of cardiotocograph (CTG): First revision (2024).

The first international consensus guideline on physiological interpretation of cardiotocograph (CTG) produced by 44 CTG experts from 14 countries was published in 2018. This guideline ensured a paradigm shift from classifying CTG by arbitrarily grouping certain features of the fetal heart rate into different "categories", and then, randomly combining them to arrive at an overall classification of CTG traces into "Normal, Suspicious and Pathological" (or Category I, II and III) to a classification which is based on the understanding of fetal pathophysiology. The guideline recommended the recognition of different types of fetal hypoxia, and the determination of features of fetal compensatory responses as well as decompensation to ongoing hypoxic stress on the CTG trace.

Relative uteroplacental insufficiency of labor.

Relative uteroplacental insufficiency of labor (RUPI-L) is a clinical condition that refers to alterations in the fetal oxygen "demand-supply" equation caused by the onset of regular uterine activity. The term RUPI-L indicates a condition of "relative" uteroplacental insufficiency which is relative to a specific stressful circumstance, such as the onset of regular uterine activity. RUPI-L may be more prevalent in fetuses in which the ratio between the fetal oxygen supply and demand is already slightly reduced, such as in cases of subclinical placental insufficiency, post-term pregnancies, gestational diabetes, and other similar conditions.

Correlation between intrapartum CTG findings and interleukin-6 levels in the umbilical cord arterial blood: A prospective cohort study.

Objective: to investigate the correlation between the intrapartum CardioTocoGraphic (CTG) findings "suggestive of fetal inflammation" ("SOFI") and the interleukin (IL)-6 level in the umbilical arterial blood.

Study Design: prospective cohort study conducted at a tertiary maternity unit and including 447 neonates born at term.

Methods: IL-6 levels were systematically measured at birth from a sample of blood taken from the umbilical artery.