Commentary: Balancing cost and benefit in antepartum fetal surveillance
For nearly 4 decades, fetal heart monitoring (FHR) has been used to assess antenatal and intrapartum fetal well-being. While both antenatal and intrapartum monitoring have come under criticism, antepartum fetal heart rate surveillance to assess the risk of fetal death and stillbirth is less controversial for the purpose for which it was intended when it was introduced in the 1970s.
This Practice Bulletin provides a review of the indications and techniques for antepartum fetal surveillance with FHR being the consistent parameter used in the assessment of fetal well-being.
Abnormal fetal surveillance is based on physiologic changes that alter fetal heart rate and fetal activity. Fetal heart rate, fetal movement, and tone in particular are impacted by uteroplacental fetal blood flow alterations and are thereby sensitive to fetal hypoxemia and acidemia. While nonreassuring fetal surveillance is associated with fetal hypoxemia and acidemia based on these physiologic adjustments, these indicators can neither predict the degree or duration of the fetal acid base disturbance nor precisely predict neonatal outcome.