Mathews Journal of Gynecology & Obstetrics


Previous Issues Volume 1, Issue 1 - 2016

Research Article Full-Text  PDF  

Abdominal Circumference Correlates with Postural Sway of the Antero-Posterior Axis in Pregnant Women

Masanori Nagai1, Mitsuo Ishida1, 4, Junko Saitoh1, 5, Yoshie Hirata2, Hatsumi Natori2, Maki Wada3

1Department of Physiology, Yamanashi Institute of Environmental Sciences, Kenmarubi 5597-1, Fujiyoshida 4030005, Japan.
2Faculty of Nursing, Yamanashi Prefectural University, Ikeda 1-6-1, Kofu 4000062, Japan.
3College of Law, Nihon University, Misaki-cho 2-3-1, Chiyoda-ku 1018375, Japan.
4Department of Health Science, Shigakukan University, Natakayama 55, Daihu 4748651, Japan.
5Division of Homeostatic Development, National Institute for Physiology, Nishigonaka 38, Myodaiji, Okazaki 4448585, Japan.

Corresponding Author:Masanori Nagai, Department of Welfare and Psychology, Health Science University, Kodachi 7187, Fujikawaguchiko 4010380, Japan. Tel: +81-555-83-5244; 
Email: [email protected]

Received Date: 12 Mar 2016   
Accepted Date: 15 Jun 2016   
Published Date: 24 Jun 2016

Copyright © 2016 Nagai M

Citation: Nagai M, Ishida M, Saitoh J, Hirata Y, et al. (2016). Abdominal Circumference Correlates with Postural Sway of the Antero-Posterior Axis in Pregnant Women. Mathews J Gynecol Obstet. 1(1): 004.



The correlation between physical features and body sway on standing upright was explored in women before and after the delivery. Body sway during upright standing was recorded in 18 women in the third trimester and 1 month after delivery. Height, body weight, body mass index (BMI), and abdominal circumference were also registered twice. In women at the 38th week of gestation on standing upright, the abdominal circumference was positively correlated with the total path length (LNG) and enveloped area (ENV-AREA) of body sway. The path length of body sway in antero-posterior axis (Y-LNG) was also correlated with the abdominal circumference, but the path length in medio-lateral axis showed no such correlation. These correlations were not observed at 1 month after delivery. The body weight and BMI did not correlate with parameters of body sway either in the 3rd trimester or postpartum. Fast Fourier transform (FFT) analysis of body sway showed that the percentile power of the frequency band of 1.0-10.0 Hz, stabilized by the somatosensory inputs, was smaller in the 3rd trimester than that postpartum. It is hypothesized that the reliance on somatosensory information for maintaining standing posture increases as the abdominal circumference increases during pregnancy.


Pregnancy; Abdominal Circumference; Stance; Postural Sway.

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