Cochrane researchers reviewed the evidence about the effectiveness of metabolomics as an evaluation tool to improve the rates of ongoing pregnancy, live birth, and miscarriage in women who were undergoing assisted reproductive technology (ART).
Metabolomics is the scientific study of the chemical ‘fingerprints’ that biological cells, tissues, or organs produce after various cellular processes. They have been proposed as a powerful non-traumatic method to assess the quality of oocytes, viability of embryos, and receptivity of the endometrium in subfertile women undergoing ART. The final aim of their use is to overcome the high incidence of multiple births and to enhance the performance of ART. However, evidence on their use remains contradictory. Therefore, it was important to evaluate the current evidence on the effectiveness of metabolomics versus conventional techniques (such as the assessment by morphology only) in providing sufficient information on the adequacy of the physiology and function of embryos, oocytes and endometrium, to facilitate targeted subfertility treatments.
We found four randomised controlled trials, with a total of 802 women, that compared metabolomic profile assessment with morphology assessment of embryos. The women were an average age of 33 years old. All studies were conducted between 2011 and 2013; length of follow-up was not specified in any of them.
Study funding sources
One study was supported by an unconditional grant from a biotechnology company (Molecular Biometrics Inc.). The very low conditional superiority for the primary outcome and premature termination of the trial were potentially associated with the funder’s interest in the results. One study received funding from a national health organisation, but the equipment was provided by Molecular Biometrics Inc., one was self-funded, while the source of funding was not stated in the fourth study.
We found low-quality evidence of no difference between the intervention and control groups in rates of live birth, ongoing pregnancy, miscarriage, clinical pregnancy, and multiple pregnancy. We found very low-quality evidence of no difference between the groups for ectopic pregnancy, and very low-quality evidence that cancellation was higher in the intervention group. Our findings suggest that if the rate of live birth or ongoing pregnancy was 36% in the non-metabolomic group, it would be between 32% and 45% with the use of metabolomics. Data were lacking on other adverse effects. No properly designed studies reported metabolomic assessment of oocyte quality or endometrium receptivity.
Quality of evidence
The overall quality of evidence ranged from low to very low. Limitations included serious risk of bias (associated with poor reporting of methods, attrition bias, selective reporting and other bias), imprecision, and inconsistency across trials.
Evidence is current to 24 November 2016.