The relationship between Cormic Index and uterine contractions’ pattern in the active phase of the first stage of labour

Abstract

Uterine contractions are indicators of labour progress. The relationship between anthropometric indices and types of childbirth has been investigated. One of these indices is referred to as the Cormic Index, which provides an estimation of the sitting height and leg length. This cross-sectional study was performed to determine the relationship between the Cormic Index and the uterine contractions’ pattern in the active phase of the first stage of labour. The standing and sitting heights of 150 pregnant women were measured to calculate the Cormic Index. Then, two Cardiotocographic traces were recorded during the 3 to 5 and 6 to 8 centimetres’ dilations, by which the uterine contractions’ pattern were determined. The mean Cormic Index was 51.84 ± 2.62. The results indicated that the Cormic Index had a positive linear correlation with MTIME (frequency of contractions) in the first monitoring episode and SDTIME (regularity of contractions) in the first and the second monitoring episode, which was significant (p < .05). However, there was no significant correlation between the Cormic Index and F:R ratio (shape of contractions) in both monitoring episodes. With the rise of the mother’s Cormic Index, the frequency of contractions in the acceleration phase, and also their regularity in the acceleration phase and the phase of the maximum slope, were decreased during the active phase of labour.

IMPACT STATEMENT

• What is already known on this subject? Uterine Contraction as an indicator of labour progress enforces cervical dilation. If uterine activity is analysed through electronic methods, one could assess labour outcome through some patterns of the contractions. Anthropometry provides a quick determination of the body proportions. The Cormic Index provides an estimation of the upper and lower body length. Several studies have investigated the relationship between the anthropometric indices and the types of childbirth. Despite the various approaches available, there is no objective means of precisely distinguishing the fact that whether labour can be successful in effecting vaginal delivery or not and diagnosis of dystocia still relies on the trial of labour.

• What do the results of this study add? The results of this study add to the growing body of research on the progression of labour that Cormic Index has a positive linear correlation with the frequency of contractions in acceleration phase, and with the regularity of contractions in the acceleration phase and the phase of maximum slope.

• What are the implications of these findings for clinical practice and/or further research? The results can help professionals to evaluate the progress of labour based on the type of uterine contractions in the latent phase or the early active phase of labour using the Cormic Index.

Keywords:

• Uterine contractions
• anthropometric
• childbirth
• heights
• leg length
• first stage labour

Acknowledgements

The present study was extracted from a dissertation approved by Mashhad University of Medical Sciences on 13 January 2013 (Project code No.: 922743) which was sponsored by the Research Deputy of the University. Hereby, the Deputy’s assistance and cooperation to perform the study are highly appreciated. The authors would also like to thank the respectful and hardworking staff in the Emergency and Maternity wards of Ommolbanin Hospital.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The study was supported by Mashhad University of Medical Sciences.