Continuous fetal heart rate monitoring in patients with preterm premature rupture of membranes undergoing expectant management

Abstract

Objective. Continuous fetal heart rate (FHR) monitoring is considered by some as necessary to the expectant management of patients with preterm premature rupture of membranes (PPROM). No data exist to support this premise, and liability may be incurred if such an order cannot be practically carried out. The purpose of our study is to evaluate the performance of prolonged FHR monitoring in terms of the completeness of recorded tracings.

Methods. A retrospective cohort study was performed between 2004 and 2006 in a tertiary care hospital on patients being expectantly managed with PPROM at 24–34 weeks of gestation. Forty-seven singleton gravidas with a physician order of continuous external FHR monitoring were included. Exclusion criteria were evidence of labour, chorioamnionitis or FHR abnormalities that prompted delivery. FHR tracings during the prolonged monitoring period were reviewed.

Results. The study cohort was monitored for a duration of 321–2272 min (mean 970 min). In total, 28.3% (95% confidence interval 23.8–33%) of the tracing did not show a legible recording. Gestational age is negatively correlated with the proportion of absent tracing, whereas body mass index is positively correlated. There is no significant difference in the absent signal proportion between the first half of the monitoring period and the second half or between day and night.

Conclusions. In patients with PPROM being expectantly managed, a significant proportion (28.3%) of the FHR tracing was not recorded as ordered. This suggests that ‘continuous’ prolonged external fetal monitoring may not be practically feasible and alternative monitoring approaches should be considered.

Keywords:

• Fetal heart rate monitoring
• preterm premature rupture of membranes
• expectant management