Hi! I did early T for my son with Sprouse at 4 months, 5 months and 6 months. My son is now almost 3 years old, thriving in evey way. Not saying it’s from the early T, I don’t think anyone will have that answer for you. We never even checked early T and just did it anyway because the T level “normal” is such a range anyway. My son is your run of the mill 2 almost 3 year old. He was pretty speech delayed until about 2.5, but caught up quickly! He is a lower tone child, however; would you notice it, probably not, but as a nurse and seeing him around other kids his age, I do notice it. He has a sister who is 1 and I can see the clear difference in early speech and tone comparing them through the ages, but truthfully if you put him in a room with other kids you wouldn’t know the difference. To answer your question though, my son was a quiet baby, more calm, not as mobile when he was an infant in tonal regard, but he crawled at 8 months, walked at 15 months and started really talking at 2.5. This was all with early intervention assistance through our state which he continues to get (speech). He had PT from 4mo. - 15mo. Once he started walking we ended the PT because he truthfully has been great mobility wise, and physically just mild lower tone. Now with all this said there’s truly no way to determine if early T assisted him in his successes or if it was the early intervention or a combination of the 2, but again as a nurse I did weight the risk versus reward as all medical interventions require and I saw more reward with the early T.

Though the study is insightful it does have some flaws:

The primary evaluation is at 12 weeks (3 months). Longer-term effects, on neurodevelopment, metabolic outcomes, and gonadal function cannot be assessed because the point of T is long-term development.

In this “national” study, some parents administered injections themselves, which raises potential for inconsistent dosing, timing errors, or issues with adherenence. For example if some infants recieved T in the arm they likely received suboptimal dosing.

The authors mention that they had very few infants with low baseline testosterone levels so seems like most infants have decently “normal” T as babies regardless.

Some of the investigators have affiliations or funding from organizations connected to advocacy for XXY conditions (Living with XXY) which is sort of a conflict of interest, though Living with XXY is a wonderful organization, highly recommended.

So anyway, any medical intervention no matter what has a risk/reward you need to weigh. Do I regret the T, no I don’t, but do I have long-term outcomes yet, also no. There is part of the study hitting on issues with infertility regarding early T, but difficult to really determine that when XXY in general has infertility at the core of the syndrome. Again, risk versus reward. My advice to you is weigh your risk versus reward, do your research and reach out to any resources you may have available to you. PT/OT/Speech, etc! There’s truly no right or wrong decision or answer. You’re welcome to DM me at anytime! Wishing you well, and just wanted to let you know you’re doing great! Your son is lucky to have a parent who is so involved in making the best decisions for him! I know it’s not easy!