Stretchable piezoresistive transducers for strain sensing have been widely developed due to their remarkable sensitivity, elasticity, and cyclability. In this work, commercial elastane yarn (Lycra® 1880 dtex) is functionalized by a conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with a dip-coating method. Poly(ethylene glycol) diacrylate (PEGDA) is used as a beneficial additive to improve the affinity between the elastic substrate and the conductive layer. Indicating a small modification of the yarn's mechanical properties, Young's modulus of 3.5 MPa is observed for the transducer. An initial resistance of 3487 Ω is measured for a length of 50 mm. After a training stage involving 100 stretching/releasing cycles to stabilize the electromechanical properties related to morphological structure, the transducer exhibits an average gauge factor of 25 for the interest strain range (0-5 %). Furthermore, the cyclability of the yarn is demonstrated by 10,000 deformation cycles with only a slight modification of the relative resistance variation.