This thesis concerns overnight ambulatory monitoring of the human fetal heart rate (FHR) using the transabdominal fetal electrocardiogram (ECG). This technique is non-invasive and provides more information on the FHR than conventional methods. However, the greatest limitation is the variation in recording success with gestational age and the time of recording. Normal FHR variability is a reliable indicator of fetal well being. During hypoxia changes in autonomic nervous system (ANS) activity results in changes in FHR variability. Therefore analysis of heart rate fluctuation enables the study of both sympathetic and parasympathetic branches of ANS. It is known that the fetal ANS matures with advancing gestation. In this thesis, the relationship between FHR parameters with gestational age was explored in fetuses of non-smoking mothers with normal pregnancies, mothers with pre-eclampsia, smokers and growth restricted fetuses. Paired day and night-time recordings were made in a majority of the women, with the aim of describing diurnal patterns of FHR parameters in the different groups and as gestation progressed. The results from overnight FHR recordings in normal recruits support the observation that basal FHR decreased with advancing gestation whilst fetal HRV and number of accelerations increased. For all FHR parameters, except for root mean square of successive difference (RMSSD), significant diurnal variation was observed in normal pregnancies. During night basal FHR decreased, whereas short-and long term FHR variability increased. Moreover, normal fetuses spent significant amount of time in high variation period and exhibited greater number of accelerations at night. On the other hand, growthI restricted fetuses and those of smokers and pre-eclamptic mothers did not exhibit diurnal variation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:664304 |
| Date | January 2014 |
| Creators | Kapaya, Habiba |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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