Validation of Non-invasive Measurement of Cardiac Output: Using Whole-Body Bio-impedance Versus Inert Gas Rebreathing in Healthy Women Undergoing In Vitro Fertilisation

Abstract Background Haemodynamic assessment in and before pregnancy is becoming increasingly important relation to complications outcomes. Different methodologies exist but there no gold-standard technique for non-invasive measurement of cardiac output (CO). We sought assess two methods CO healthy women undergoing vitro fertilisation cycles (IVF). This was a prospective longitudinal study 71 aged 18–44 years planning IVF measurements obtained via inert gas rebreathing (IGR) using Innocor ™ whole-body bio-impedance (WBI) Nicas the reproducibility between methods. Four visits occurred at which both techniques were used: initial assessment, embryo transfer, day test 4 weeks post-transfer (regardless whether conception occurred). Cross-sectional agreement assessed calculation bias, percentage error limits (LOA) Bland–Altman analysis. Longitudinal 4-quadrant plot with concordance rate, angular bias radial (%). Results One hundred thirteen from 44 participants suitable cross-sectional (Bland–Altman) IGR (Innocor ) Mean 4.61 L/min 5.05 WBI (Nicas ). The 0.44 L/min. 76% intra-correlation coefficient 0.135 (95% CI −0.43–0.306). Fifty-nine 28 (4Q-plot) rate 64.4%, – 0.14, + − 13.25°. Conclusion There poor techniques. These cannot be used interchangeably when measuring IVF, these results may more generalizable, peri-conception period.