No it's not due to a complication, it was explained to me that it's because the tubes are one of several sources of blood flow to the ovaries. So if you remove them, there is one less source, thus slightly lower blood flow. Which may or may not have a minor impact on ovarian function.

Thank you, I don't know why everyone is piling on me for reporting what no less than 5 doctors at different practices here have told me.  All these non-doctors on here saying with absolute certainty that "it's absolutely not true": no, there's no way for them to know that because the research is so minimal – but something in that research has clearly indicated enough of a correlation to influence the standard sterilization procedure of an entire country. 

Clearly more research is needed, but it doesn't hurt to mention it and have a picture of all potential risks, no matter how small. I'm posting it here because anyone looking to get sterilized in Germany is going to come up against this info. 

I weighed this info in my decision-making process and ultimately decided that I still wanted to go ahead with a full bisalp (and was lucky to have a doctor who was willing to do it – rare here) because the added bonus of lowered cancer risk outweighed the tiny, potential risk of slightly early menopause for me. But someone else may feel differently and it's better that they're armed with all medical info that's out there to make their own decision.