Predictors of Postoperative Pain Following Oocyte Retrieval for Assisted Reproduction

The central objective of this study will be to evaluate the relationship between estrogen levels and the pain following oocyte retrieval in women undergoing in vitro fertilization.

Subject will undergo standard clinical protocols for the entire oocyte stimulation cycle and all assisted reproductive procedure decisions and algorithms will be decided entirely independent of this study. The anesthetic and postoperative pain regimens will use the same agents and dose ranges used in clinical standard practice; however, the regimens will be standardized, so as to limit confounding variables. The study regimen for anesthesia will differ from the current, clinical standard by the mandated use of actual body weight (in current practice, actual, adjusted ideal, or ideal body weights are used), the use of fentanyl 1 mcg/kg IV (instead of 100 mcg for everyone), and the standardization of postoperative analgesia (noted below). The total amount of fentanyl, propofol, and postoperative drugs will be recorded. Postoperative analgesia will be standardized based on the subject's self reported verbal analogue score (VAS) and the timing of the report. The agents and timing used below differ from the current clinical standard by assessing VAS and responding with a certain regimen.

Protocolized analgesia based on VAS degree of discomfort and time. Analgesic options include heating pad, acetaminophen, percocet (oxycodone), fentanyl 0.5-1 mcg/kg.

Change in discomfort following oocyte retrieval with standardized anesthesia management as measured by verbal analogue scoring (0-10 scale). VAS scores correlate to minimal (VAS 0-3), moderate (VAS 4-6) or severe (VAS ≥7) discomfort.

Change in discomfort following oocyte retrieval with standardized anesthesia management as measured by verbal analogue scoring (0-10 scale) after immediate postoperative period (1 hrs) but prior to Embryo Transfer on 3rd postoperative day. Visual Analogue Scale (VAS) scores correlate to minimal (VAS 0-3), moderate (VAS 4-6) or severe (VAS ≥7) discomfort. Patients will record the type, dose, and timing of pain medicines in a diary to be returned at Embryo Transfer.

Inclusion Criteria: American Society of Anesthesiologists (ASA) I to III health status (moderate systemic disease), Age between 18 and 50 yrs Undergoing oocyte retrieval with intravenous general anesthesia. Exclusion Criteria: Refuse or withdraw their consent Fail to adequately respond to IVF stimulations medications, and thus are not eligible for oocyte retrieval.

Harnett MJ, Bhavani-Shankar K, Datta S, Tsen LC. In vitro fertilization-induced alterations in coagulation and fibrinolysis as measured by thromboelastography. Anesth Analg. 2002 Oct;95(4):1063-6, table of contents. doi: 10.1097/00000539-200210000-00050.

Bader AM, Datta S, Moller RA, Covino BG. Acute progesterone treatment has no effect on bupivacaine-induced conduction blockade in the isolated rabbit vagus nerve. Anesth Analg. 1990 Nov;71(5):545-8. doi: 10.1213/00000539-199011000-00016.

Datta S, Lambert DH, Gregus J, Gissen AJ, Covino BG. Differential sensitivities of mammalian nerve fibers during pregnancy. Anesth Analg. 1983 Dec;62(12):1070-2.