The increased rate of emergency caesarean section in pregnant women with diabetes may be explained by poor uterine contractility, according to researchers from the University of Liverpool.

Their data demonstrated that compared with nondiabetic women, those with diabetes had reduced intracellular calcium signals and expression of calcium entry channels. In addition, these women had a reduction in muscle content, as determined by histological examination.

Researchers compared spontaneous, high potassium depolarization and oxytocin-induced contractions in women with diabetes (n=40) and matched controls (n=68) having elective caesarean section. Intracellular calcium was measured to determine the mechanism of differences. In addition, western blotting was performed and the tissues were histologically compared.

Compared with controls, diabetic women had significantly decreased contraction amplitude (2.4 mN vs. 1.5 mN; P<.05) and duration in uteri (1.7 min vs. 0.9 min; P<.05). This was true after controlling for cofounders such as BMI.

According to researchers, reduced contractility was persistent after comparing insulin-treated patients with diet-controlled patients with gestational diabetes.

“Contractility was poorer in the diabetic samples whether arising spontaneously, with oxytocin or high [potassium]; calcium channel expression and signaling were reduced and are likely to account for the reduction in contractility,” they wrote.

In patients with diabetes, myometrium was responsive to oxytocin but did not reach levels found in patients without diabetes.

“The underlying mechanism is related to reduced [calcium] channel expression in intracellular calcium signals and a decrease in muscle mass. We conclude that these factors significantly contribute to the increased emergency caesarean section rate in diabetic patients,” the researchers said.

Source:Endocrine Today