In-vitro Myometrial Contractility After Oxytocin Pre-exposure in Women With Advanced Maternal Age and Morbid Obesity

Women with advanced maternal age and morbid obesity, have a higher incidence of labor induction/ augmentation and cesarean section (CS), and are at a greater risk for postpartum hemorrhage (PPH). Oxytocin is the first line drug in the treatment of PPH, however, oxytocin receptor (OTR) desensitization has been recognized in the context of prolonged labors secondary to either endogenous or exogenous oxytocin exposure. It is unknown if oxytocin desensitization specifically affects contractility in women with advanced maternal age and morbid obesity when compared to younger or normal weight populations. Further it is not known if the higher incidence of PPH seen in these women is due to poor uterine contractility and/or poor response to oxytocin. The investigators hypothesize that women with advanced maternal age and morbid obesity will exhibit poor myometrial contractility as compared to women that are younger and of normal body habitus, in both oxytocin pre-treated and untreated myometrium.