Antepartum fetal monitoring is best organized as a stepwise progression through clinical assessment, ultrasound measurement of growth, Doppler assessment of flow velocity waveforms and cardiotocography. The starting point in this sequence depends on the level of assessed risk. Similarly, intrapartum monitoring is performed according to level of risk, so that low-risk fetuses can be monitored effectively using intermittent techniques, while high-risk fetuses should be monitored using cardiotocography. Fetal blood sampling and pH estimation should be used to further investigate fetuses with changes in the fetal heart rate pattern thought to be indicative of hypoxia. Such further investigation is not appropriate if the problem appears to be infection, a risk of meconium aspiration or uterine scar rupture, when a decision about the appropriate mode of delivery needs to be taken on clinical grounds.
ABSTRACT