Poor uterine contractility in obese women
Article first published online: 25 JAN 2007
2007 The Authors Journal compilation
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 114, Issue 3, pages 343–348, March 2007
How to Cite
Zhang, J., Bricker, L., Wray, S. and Quenby, S. (2007), Poor uterine contractility in obese women. BJOG: An International Journal of Obstetrics & Gynaecology, 114: 343–348. doi: 10.1111/j.1471-0528.2006.01233.x
- Issue published online: 25 JAN 2007
- Article first published online: 25 JAN 2007
- Accepted 19 November 2006. Published OnlineEarly 25 January 2007.
- Caesarean section;
- myometrial contractility;
Objective The aim of the study was to elucidate the reason for the high rate of caesarean section in obese women. We examined the following hypotheses: (1) obese women have a high incidence of complications related to poor uterine contractility—caesarean section for dysfunctional labour and postpartum haemorrhage. 2) The myometrium from obese women has less ability to contract in vitro.
Design First, a clinical retrospective analysis of data from 3913 completed singleton pregnancies was performed. Secondly, in a prospective study the force, frequency and intracellular [Ca2+] flux of spontaneously contracting myometrium were related to the maternal body mass index.
Setting Liverpool Women’s Hospital and University of Liverpool.
Population The clinical study involved all women who delivered in one hospital in 2002. The in vitro study myometrial biopsies were obtained from 73 women who had elective caesarean section at term.
Results Maternal obesity carried significant risk of caesarean section in labour that was highest for delay in the first stage of labour (OR 3.54). The increased risk of caesarean section in obese women largely occurred in women with normal- and not with high-birthweight infants. Obese women delivering vaginally had increased risk of prolonged first stage of labour and excessive blood loss. Myometrium from obese women contracted with less force and frequency and had less [Ca2+] flux than that from normal-weight women.
Conclusions We suggest that these findings indicate that obesity may impair the ability of the uterus to contract in labour.