There are people who are born female without a functional or developed reproductive tract - guess "science" says they aren't women! Regardless, this question has been already looked into for decades, but as this seems to be your first time asking the question and you apparently have done zero research of your own, this will get you started:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8955456/
"These findings add support to the notion that the underlying brain anatomy in transgender people is shifted away from their biological sex towards their gender identity."
There are many, many, many more studies that show similar findings.
"Some (or perhaps all) of the aforementioned variables may have contributed to neuroanatomical variations in transgender brains, as repeatedly observed in both
post mortem and in vivo studies published over the past three decades [
10,
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The standard definition still applies although there will always be certain exceptions due to medical illness. For example - chromosomal XY males who have androgen insensitivity syndrome develop as females due to failure to response to testosterone, and subsequent aromatisation to estrogen. They are completely feminised due to a complete lack of action from testosterone. All of us have both testosterone and estrogen receptors. Strip a man away from testosterone and inject him with estrogen and you'll see what will occur. On that same note, environmental estrogens are ubiqitous and may explain the rise of modern day trends. I should note our brains have a degree of neuroplasticity.
The sample sizes are also rather small but yes there are some studies which indicate there could be potential neuroanatomical differences. However, from some of your references:
"
Rather than being merely shifted towards either end of the male-female spectrum,
transgender persons seem to present with their own unique brain phenotype. Mueller SC, Guillamon A, Zubiaurre-Elorza L, et al. The Neuroanatomy of Transgender Identity: Mega-Analytic Findings From the ENIGMA Transgender Persons Working Group. J Sex Med 2021;18:1122-1129."
"Results revealed that
regional gray matter variation in MTF transsexuals is more
similar to the pattern found in men than in women." Luders E, Sánchez FJ, Gaser C, Toga AW, Narr KL, Hamilton LS, Vilain E. Regional gray matter variation in male-to-female transsexualism. Neuroimage. 2009 Jul 15;46(4):904-7. doi: 10.1016/j.neuroimage.2009.03.048. Epub 2009 Mar 31. PMID: 19341803; PMCID: PMC2754583.
"The present data
do not support the notion that brains of MtF-TR are feminized. The observed changes in MtF-TR bring attention to the networks inferred in processing of body perception." Savic I, Arver S. Sex dimorphism of the brain in male-to-female transsexuals. Cereb Cortex. 2011 Nov;21(11):2525-33. doi: 10.1093/cercor/bhr032. Epub 2011 Apr 5. PMID: 21467211.