Abstract
Background The likelihood of cesarean is in part related to maternal body mass index (BMI).
Myometrial changes may be responsible.
Methods Myometrial biopsies were collected from the upper edge of the hysterotomy from women
undergoing scheduled cesarean with term, singleton gestations. Oxytocin receptor and
connexin-43 mRNA protein expression was quantified with real-time polymerase chain
reaction and Western blot.
Results Twenty subjects were recruited: 13 repeat and 7 primary cesareans. Oxytocin receptor
mRNA was associated with BMI among women undergoing primary (r = 0.75; p = 0.05) but not repeat cesarean (p > 0.05). Controlling for gestational age, this association strengthened (p = 0.004). Receptor protein expression showed a linear correlation with BMI in the
primary cesarean group (p = 0.002). Connexin-43 mRNA expression was not related to BMI in women undergoing primary
(r = −0.14, p = 0.76) or repeat (r = −0.01, p = 0.86) cesarean.
Conclusions Oxytocin receptor, but not connexin-43, expression is related to BMI, suggesting
an alteration in oxytocin receptor expression or function related to obesity.
Keywords
cesarean delivery - connexin-43 - obesity - oxytocin receptor - pregnancy
