Can you get women pregnant on cycle?
About 10 years ago the general consensus was that men who were on steroids (especially a long time), would be unable to impregnate their wives, girlfriends, etc. Of course we have learned over time this is untrue. How do we know for sure? Well a lot of guys online have openly stated they have gotten their significant other pregnant while on heavy cycles of prohormones or anabolic androgenic steroids (AAS). We do know that sperm production is in fact inhibited ON cycle. But what we also now know is that sperm is still produced, which as you know means you can still get females pregnant.
I recently heard an interesting theory (I forget where at the moment), that in cycles that contain extremely high doses of anabolics there is actually some sort of reverse gonadotropin response in which sperm production is drastically increased. I have no idea if there is any legitimate science that supports this theory (I seriously doubt it), but who knows. We have seen several IFBB pros, who are presumed to be on heavy AAS cycles, get their wives pregnant.
Sperm Rebound – Not Rebound Gyno
This leads me to a 2003 study in about 300 chinese men. The purpose of the study was to test the efficacy of testosterone undecanoate as a male birth control option. This was the first ever study to describe “sperm rebound”. Before I explain the “sperm rebound” I’ll first explain how they “suppressed” their natural testosterone, and sperm production.
First they gave them an injection of 1,000 mg’s of testosterone undecanoate, and continued to give them 500 mg’s per month until they reached azoospermia or severe oligozoospermia. Azoospermia is not a fun exhibit at a zoo, but rather it is a condition where there is no measurable sperm count in men, while oligozoospermia is simply a sperm count of less than 3 million sperm/ml. Of the 308 guys who underwent this “suppression” process, all but 9 reached at least severe oligozoospermia or worse (azoospermia). Meaning in this case, testosterone undecanoate was a pretty effective male birth control to some degree.
After the “suppression” phase of the study, the continued giving the men 500 mg’s of testosterone undecanoate every 30 to 45 days. If any of the men experienced “sperm rebound” they discontinued the testosterone undecanoate injections. They defined sperm round as any man who had a sperm count of 3 million sperm/ml or more. Of the 296 men studied, only 6 of them experienced sperm rebound or 2% (one of which got their wife pregnant). This seems small, but overall it’s actually quite rare to hear of a guy getting a girl pregnant on cycle. The authors do not seem to know why 6 of the men experienced sperm rebound, they simply call them “non-responders”.
Testosterone Undecanoate as Birth Control
Of course none of this lends a huge amount of confidence in drug makers ability to suppress sperm, and create a usable male birth control option. One interesting note is that it took as long as 108 days (on average) to reach azoospermia, so if you plan to rely on testosterone undecanoate for EXTRA protection you may want to plan at least a 15 week cycle.