Monitoring of stimulated cycles in assisted reproduction (IVF and ICSI)

BACKGROUND: Traditional monitoring of ovarian hyperstimulation during in vitro fertilisation (IVF) treatment has included ultrasonography plus serum estradiol concentration to ensure safe practice by reducing the incidence and severity of ovarian hyperstimulation syndrome (OHSS). The need for intensive monitoring during ovarian stimulation in IVF is controversial. It has been suggested that close monitoring is time consuming, expensive and inconvenient for the woman and simplification of IVF therapy by using ultrasound only should be considered. This systematic review assessed the effects of ovarian monitoring by ultrasound only versus ultrasound plus serum estradiol measurement on IVF outcomes and the occurrence of OHSS in women undergoing stimulated cycles in IVF and intra-cytoplasmic sperm injection (ICSI) treatment. OBJECTIVES: To quantify the effect of monitoring controlled ovarian stimulation in IVF and ICSI cycles with ultrasound plus serum estradiol concentration versus ultrasound only in terms of live birth rates, pregnancy rates and the incidence of OHSS. SEARCH STRATEGY: We searched the Menstrual Disorders and Subfertility Group Specialised Register of controlled trials, Cochrane Central Register of Controlled Trials (CENTRAL) on the latest issue of The Cochrane Library, MEDLINE (1966 to May 2007), EMBASE (1980 to May 2007), CINAHL (1982 to May 2007), the National Research Register, and web-based trial databases such as Current Controlled Trials. There was no language restriction. Additionally all references in the identified trials and background papers were checked and authors were contacted to identify relevant published and unpublished data. SELECTION CRITERIA: Only randomised controlled trials that compared monitoring with ultrasound plus serum estradiol concentration versus ultrasound only in women undergoing ovarian hyperstimulation for IVF and ICSI treatment were included. DATA COLLECTION AND ANALYSIS: Two review authors independently examined the electronic search results for relevant trials, extracted data and assessed trial quality. They resolved disagreements by discussion with two other authors. Outcomes data were pooled when appropriate and summary statistics presented when limited data did not allow meta-analysis. MAIN RESULTS: Our search strategy identified 1119 potentially eligible reports, of which two met our inclusion criteria. These involved 411 women who underwent controlled ovarian stimulation monitoring. Our primary outcome of live birth rate was not reported in either study. One trial reported clinical pregnancy rate per woman (33% versus 31%; RR 1.07, 95% CI 0.77 to 1.49), the second trial reported clinical pregnancy rate per oocyte retrieval (22% versus 25%). There was no significant difference between the ultrasound plus estradiol group and the ultrasound alone group in the mean number of oocytes retrieved (WMD -0.55, 95% CI -1.79 to 0.69) and the incidence of ovarian hyperstimulation (RR 0.73, 95% CI 0.30 to 1.78) for the two studies. AUTHORS' CONCLUSIONS: There is no evidence from randomised trials to support cycle monitoring by ultrasound plus serum estradiol as more efficacious than cycle monitoring by ultrasound only on outcomes of live birth and pregnancy rates. A large well-designed randomised controlled trial is needed that reports on live birth rates and pregnancy, with economic evaluation of the costs involved and the views of the women undergoing cycle monitoring. A randomised trial with sufficiently large sample size to test the effects of different monitoring protocols on OHSS, a rare outcome, will pose a great challenge. Until such a trial is considered feasible, cycle monitoring by transvaginal ultrasound plus serum estradiol may need to be retained as a precautionary good practice point.