The American Psychology Association has released a peer reviewed paper on the varying PTSD symptoms with lower levels of estrogen. The variance in the studied cases shows that women with low estrogen and exposed to trauma, suffer from more reactivity/response in the sympathetic nervouse system (aka fight-or-flight response).
The impact statement <doi.apa.org/doiLanding?doi=10.1037%2Ftra0001113> from the paper reads:
We show that lower estradiol is associated with greater number and severity of self-reported PTSD symptoms in naturally cycling women with a history of trauma exposure. In addition, trauma-exposed women in low- versus high-estradiol menstrual cycle phases show greater sympathetic and lower hypothalamic-pituitary-adrenal axis reactivity to a trauma reminder, more severe daily PTSD symptoms, and more variable daily affect. These results have potential implications for clinical assessment, as menstrual cycle phase at the time of assessment could influence PTSD diagnosis. Additionally, clinicians working with women with PTSD might anticipate greater affective lability and increased symptoms during low-estradiol menstrual cycle phases. (PsycInfo Database Record (c) 2021 APA, all rights reserved)