Implementation of a novel continuous fetal Doppler (Moyo) improves quality of intrapartum fetal heart rate monitoring in a resource-limited tertiary hospital in Tanzania: An observational study

Abstract

Background: Intrapartum Fetal Heart Rate (FHR) monitoring is crucial for the early detection of abnormal FHR, facilitating timely obstetric interventions and thus the potential reduction of adverse perinatal outcomes. We explored midwifery practices of intrapartum FHR monitoring pre and post implementation of a novel continuous automatic Doppler device (the Moyo).

Methodology: A pre/post observational study among low-risk pregnancies at a tertiary hospital was conducted from March to December 2016. In the pre-implementation period, intermittent monitoring was conducted with a Pinard stethoscope (March to June 2016, n = 1640 women). In the post-implementation period, Moyo was used for continuous FHR monitoring (July-December 2016, n = 2442 women). The primary outcome was detection of abnormal FHR defined as absent, FHR<120or FHR>160bpm. The secondary outcomes were rates of assessment/documentation of FHR, obstetric time intervals and intrauterine resuscitations. Chi-square test, Fishers exact test, t-test and Mann-Whitney U test were used in bivariate analysis whereas binary and multinomial logistic regression were used for multivariate.

Results: Moyo use was associated with greater detection of abnormal FHR (8.0%) compared with Pinard (1.6%) (p<0.001). There were higher rates of non-assessment/documentation of FHR pre- (45.7%) compared to post-implementation (2.2%) (p<0.001). At pre-implementation, 8% of deliveries had FHR documented as often as ≤ 60 minutes, compared to 51% post-implementation (p<0.001). Implementation of continuous FHR monitoring was associated with a shorter time interval from the last FHR assessment to delivery i.e. median (IQR) of 60 (30,100) to 45 (21,85) minutes (p<0.001); and shorter time interval between each FHR assessment i.e. from 150 (86,299) minutes to 60 (41,86) minutes (p<0.001). Caesarean section rates increased from 2.6 to 5.4%, and vacuum deliveries from 2.2 to 5.8% (both p<0.001). Perinatal outcomes i.e. fresh stillbirths and early neonatal deaths were similar between time periods. The study was limited by both lack of randomization and involvement of low-risk pregnant women with fewer adverse perinatal outcomes than would be expected in a high-risk population.

Conclusion: Implementation of the Moyo device, which continuously measures FHR, was associated with improved quality in FHR monitoring practices and the detection of abnormal FHR. These improvements led to more frequent and timely obstetric responses. Follow-up studies in a high-risk population focused on a more targeted description of the FHR abnormalities and the impact of intrauterine resuscitation is a critical next step in determining the effect on reducing perinatal mortality.

Fig 1. Moyo–The new continuous fetal heart rate monitor (Laerdal Global Health).

FHR abnormalities defined as absent, FHR<120 or FHR>160bpm).

Fig 2. Flow chart of the study population.

Fig 3. Frequency of Fetal Heart Rate monitoring and documentation post-implementation vs pre-implementation of the Moyo.