The utility of nuclear magnetic resonance spectroscopy in assisted reproduction

Abstract

Infertility affects approximately 15-20% of individuals of reproductive age worldwide. Over the last 40 years, assisted reproductive technology (ART) has helped millions of childless couples. However, ART is limited by a low success rate and risk of multiple gestations. Devising methods for selecting the best gamete or embryo that increases the ART success rate and prevention of multiple gestation has become one of the key goals in ART today. Special emphasis has been placed on the development of non-invasive approaches, which do not require perturbing the embryonic cells, as the current morphology-based embryo selection approach has shortcomings in predicting the implantation potential of embryos. An observed association between embryo metabolism and viability has prompted researchers to develop metabolomics-based biomarkers. Nuclear magnetic resonance (NMR) spectroscopy provides a non-invasive approach for the metabolic profiling of tissues, gametes and embryos, with the key advantage of having a minimal sample preparation procedure. Using NMR spectroscopy, biologically important molecules can be identified and quantified in intact cells, extracts or secretomes. This, in turn, helps to map out the active metabolic pathways in a system. The present review covers the contribution of NMR spectroscopy in assisted reproduction at various stages of the process.

Keywords: assisted reproductive technology; in vitro fertilization; metabolomics; nuclear magnetic resonance spectroscopy; systems biology.

Figure 1.

Schematic illustration representing the key steps involved in an NMR-based metabolomics study.

Figure 2.

Illustration of assignment of peaks and identification of metabolites from NMR. The 1D and 2D NMR spectra recorded on a mixture of glucose and alanine sample is shown.

Figure 3.

Schematic of the utility of NMR spectroscopy in assisted reproduction and a variety of sample types that have been studied using NMR spectroscopy.

Figure 4.

One-dimensional proton NMR spectrum of a one-step embryo culture medium (Vitromed) with peak assignments shown for metabolites.