Pain relief for women undergoing oocyte retrieval for assisted reproduction

Various methods of conscious sedation and analgesia have been used for pain relief during oocyte recovery in in vitro fertilisation (IVF) and intra-cytoplasmic sperm injection (ICSI) procedures. The choice of agent has also been influenced by the quality of sedation and analgesia as well as by concerns about possible detrimental effects on reproductive outcomes.

To assess the effectiveness and safety of different methods of conscious sedation and analgesia on pain relief and pregnancy outcomes in women undergoing transvaginal oocyte retrieval.

We searched the Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL (from their inception to present); the National Research Register and Current Controlled Trials. We searched reference lists of included studies for relevant studies and contacted authors for information on unpublished and ongoing trials. There was no language restriction. The search was updated in July 2012.

Only randomised controlled trials comparing different methods of conscious sedation and analgesia for pain relief during oocyte recovery were included.

Quality assessment and data extraction were performed independently by two review authors. Interventions were classified and analysed under broad categories or strategies of sedation and pain relief to compare different methods and administrative protocols of conscious sedation and analgesia. Outcomes were extracted and the data were pooled when appropriate.

With this update, nine new studies were identified resulting in a total of 21 trials including 2974 women undergoing oocyte retrieval. These trials compared five different categories of conscious sedation and analgesia: 1) conscious sedation and analgesia versus placebo; 2) conscious sedation and analgesia versus other active interventions such as general and acupuncture anaesthesia; 3) conscious sedation and analgesia plus paracervical block versus other active interventions such as general, spinal and acupuncture anaesthesia; 4) patient-controlled conscious sedation and analgesia versus physician-administered conscious sedation and analgesia; and 5) conscious sedation and analgesia with different agents or dosage. Evidence was generally of low quality, mainly due to poor reporting of methods, small sample sizes and inconsistency between the trials.Conflicting results were shown for women's experience of pain. Compared to conscious sedation alone, more effective pain relief was reported when conscious sedation was combined with electro-acupuncture: intra-operative pain mean difference (MD) on 1 to 10 visual analogue scale (VAS) of 3.00 (95% CI 2.23 to 3.77); post-operative pain MD in VAS units of 2.10 (95% CI 1.40 to 2.80; N = 61, one trial, low quality evidence); or paracervical block (MD not calculable).The pooled data of four trials showed a significantly lower intra-operative pain score with conscious sedation plus paracervical block than with electro-acupuncture plus paracervical block (MD on 10-point VAS of -0.66; 95% CI -0.93 to -0.39; N = 781, 4 trials, low quality evidence) with significant statistical heterogeneity (I(2) = 76%). Patient-controlled sedation and analgesia was associated with more intra-operative pain than physician-administered sedation and analgesia (MD on 10-point VAS of 0.60; 95% CI 0.16 to 1.03; N = 379, 4 trials, low quality evidence) with high statistical heterogeneity (I(2) = 83%). Post-operative pain was reported in only nine studies. As different types and dosages of sedative and analgesic agents, as well as administrative protocols and assessment tools, were used in these trials the data should be interpreted with caution.There was no evidence of a significant difference in pregnancy rate in the 12 studies which assessed this outcome, and pooled data of four trials comparing electro-acupuncture combined with paracervical block with conscious sedation and analgesia plus paracervical block showed an odds ratio (OR) of 0.96 (95% CI 0.72 to 1.29; N = 783, 4 trials) for pregnancy. High levels of women's satisfaction were reported for all modalities of conscious sedation and analgesia as assessed in 12 studies. Meta-analysis of all the studies was not attempted due to considerable heterogeneity.For the rest of the trials a descriptive summary of the outcomes was presented.

The evidence from this review of 21 randomised controlled trials did not support one particular method or technique over another in providing effective conscious sedation and analgesia for pain relief during and after oocyte recovery. The simultaneous use of more than one method of sedation and pain relief resulted in better pain relief than one modality alone. The various approaches and techniques reviewed appeared to be acceptable and were associated with a high degree of satisfaction in women. As women vary in their experience of pain and in coping strategies, the optimal method may be individualised depending on the preferences of both the women and the clinicians and resource availability.