Pre-ovarian block versus paracervical block for oocyte retrieval.

BACKGROUND A pre-ovarian block (POB) technique can be used for pain relief during oocyte retrieval in IVF. The local anaesthetic is deposited in the vaginal wall and between the vaginal wall and the peritoneal surface near the ovary using ultrasound guidance. The aim of this study was to test whether analgesia with POB resulted in improved pain relief compared to paracervical block (PCB). METHODS A prospective, randomized, multicentre study of POB versus PCB (10 ml of 1% lidocaine each) with 183 patients randomized to POB (n = 96) or PCB (n = 87) was performed. Randomization (via a computer-generated list) was balanced for age, previously completed IVF cycles, degree of anxiety, estimated number of follicles, BMI, premedication and centre. Pain was measured using a visual analogue scale (VAS, 0-100 mm) and given as median values. The primary end-point of this study was overall VAS pain score for both sides during the oocyte retrieval procedure. RESULTS Overall pain during the entire oocyte retrieval was 22 (POB) and 16 (PCB) (P = 0.42). No differences were found in degree of anxiety, premedication, dose of alfentanil, fertilization rate, number of good-quality embryos or clinical pregnancy rate. CONCLUSIONS No differences were found in overall pain experienced during the entire oocyte retrieval procedure with POB compared to PCB.