Oocyte Retrieval of Few Follicles Does Not Require Analgesia: a Large-scale Multicentre Pain Analysis

Research Question: What is the pain intensity of oocyte retrieval (OCR) without anaesthesia and analgesia in women with a low or medium number of follicles?

Design: Multicentre observational study analysing IVF cycles without anaesthesia and analgesia in seven IVF centres in Germany and Switzerland between January 2022 and March 2023. In total, 2290 cycles of natural cycle IVF or minimal stimulation IVF from 1039 patients were recorded. Pain score was assessed using a VAS graded 0 to 10. A descriptive analysis was conducted, followed by a statistical evaluation using a linear mixed model to analyse the effect on the pain score of the number of oocytes retrieved and the number of repeated IVF cycles.

Results: The number of oocytes retrieved varied from 0 to 16 (IQR 1-2). Pain score varied from 0 to 10, with a median pain score of 3.0 (IQR 2-4), defined as 'mild' pain. Compared with a reference value of aspirations with one oocyte, the pain score increased slightly by 0.5 points if no oocyte was retrieved, by 0.42 points if two to five oocytes were retrieved and by 1.14 points if six or more oocytes were retrieved, all with little clinical relevance. Pain decreased slightly with repeated aspirations (-0.05 points per cycle) (P = 0.028). The complication rate requiring hospitalization per aspiration was less than 0.1%.

Conclusion: Pain intensity during OCR of one or few follicles is mild. Therefore, OCR can be offered without anaesthesia and analgesia to reduce aspiration time and cost.