“…We equally noted a high improvement rate of 82.5% for TTH. This is higher than the improvement rate of 39.6% reported by Karli et al 14 and the rate reported previously by other authors. 18 Although the precise mechanism for this improvement is not yet elucidated, there is consensus about the role of the level of estrogen and progesterone during pregnancy and their influence on peripheral and central pain transmission via serotonergic, noradrenergic, glutamatergic, GABAergic and opioidergic neurotransmitter systems.…”