  Recent neutron scattering and transport data obtained on underdoped YBCO,
with strong signatures of rotation symmetry breaking at low temperatures, point
toward electron-nematic order in the charge sector. Such order may originate
from a uniform distortion with d-wave symmetry or as a precursor of a
uni-directional stripe phase. Here, we discuss whether the neutron scattering
data can be linked to incipient charge stripes. We employ and extend a
phenomenological model for collective spin and charge fluctuations and analyze
the resulting spin excitation spectrum under the influence of lattice
anisotropies. Our results show that the experimentally observed
temperature-dependent magnetic incommensurability is compatible with a scenario
of incipient stripes, the temperature dependence being due to the temperature
variation of both strength and correlation length of the charge stripes.
Finally, we propose further experiments to distinguish the possible theoretical
scenarios.
