Linear and non-linear analysis of uterine contraction signals obtained with tocodynamometry in prediction of operative vaginal delivery

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Hernani Goncalves (Author) FMUP; Morais, M (Author) Other; Pinto, P (Author) FMUP; Ayres de Campos, D (Author) Other; Joao Bernardes (Author) FMUP

Journal

Title: Journal of Perinatal Medicine

Vol. 45

Pages: 327-332

ISSN: 0300-5577

Publisher: Walter De Gruyter

Indexing

ISI Web of Knowledge - 4 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-00M-NH9

DOI: 10.1515/jpm-2016-0036

Abstract (EN): Objective: The aim of this study was to explore whether linear and non-linear analysis of uterine contraction (UC) signals obtained with external tocodynamometry can predict operative vaginal delivery (OVD). Materials and methods: The last 2 h before delivery (H 1 and H 2) of 55 UC recordings acquired with external tocodynamometry in the labour ward of a tertiary care hospital were analysed. Signal processing involved the quantification of UCs/segment (UC N), and the linear and non-linear indices: Sample Entropy (SampEn) measuring signal irregularity; interval index (II) measuring signal variability, both of which may be associated with uterine muscle fatigue, and high frequency (HF), associated with maternal breathing movements. Thirty-two women had normal deliveries and 23 OVDs. Statistical inference was performed using 95% confidence intervals (95% CIs) for the median, and areas under the receiver operating curves (auROCs), with univariate and bivariate analyses. Results: A significant association was found between maternal body mass index (BMI) and UC signal quality in H 1, with moderate/poor signal quality being more frequent with higher maternal BMI. There was an overall increase in contraction frequency (UC N), signal regularity (SampEn), signal variability (II), and maternal breathing (HF) from H 1 to H 2. The OVD group exhibited significantly higher values of signal irregularity and variability (SampEn and II) in H 1, and higher contraction frequency (UC N) and maternal breathing (HF) in H 2. Modest auROCs were obtained with these indices in the discrimination between normal and OVDs. Conclusions: The results of this exploratory study suggest that analysis of UC signals obtained with tocodynamometry, using linear and non-linear indices associated with muscle fatigue and maternal breathing, identifies significant changes occurring during labour, and differences between normal and OVDs, but their discriminative capacity between the two types of delivery is modest. Further refinement of this analysis is needed before it may be clinically useful.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6