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Obesity is a worldwide public health problem, affecting at least one-third of
pregnant women. One of the main problems of obesity during pregnancy is the high rate of
cesarean section. The leading cause of this higher frequency of cesarean sections in obese
women compared with that in nonobese women is an altered myometrial function that leads
to lower frequency and potency of contractions. In this article, we review the disruptions of
myometrial myocytes in obese women during pregnancy that may explain dysfunctional
labor. The myometrium of obese women exhibited lower expression of connexin43, lower
function of the oxytocin receptor, and higher activity of the potassium channels.
Adipokines, such as leptin, visfatin, and apelin, whose concentrations are higher in obese
women, decreased myometrial contractility, perhaps by inhibiting the myometrial
RhoA/ROCK pathway. The characteristically higher cholesterol levels of obese women
alter myometrial myocyte cell membranes, especially the caveolae, inhibiting oxytocin
receptor function and increasing the K+
channel activity. All these changes in the
myometrial cells or their environment decrease myometrial contractility, perhaps at least
partially explaining the higher rate cesarean of sections in obese women.