From a purely observation perspective, pornography consumption has increased dramatically at the same time as falling fertility. Even if a mechanism isn't obvious, it at least seems like there is a possibility of a connection.
Studies have indicated that long-term pornography use correlates with erectile dysfunction and loss of interest in sexual relationships. It's not hard to imagine that fertility might be related to these other aspects of reproductive health. Unfortunately few long-term studies seem to focus on fertility specifically.
Short term studies on the influence of porn find that novel sexual stimulus seems to increase sperm quality while it attenuates in response to repeated exposure to the same stimulus. This is bad news for real life humans who cannot change as rapidly or dramatically as one can switch videos.
Studies have indicated that long-term pornography use correlates with erectile dysfunction and loss of interest in sexual relationships. It's not hard to imagine that fertility might be related to these other aspects of reproductive health. Unfortunately few long-term studies seem to focus on fertility specifically.
Short term studies on the influence of porn find that novel sexual stimulus seems to increase sperm quality while it attenuates in response to repeated exposure to the same stimulus. This is bad news for real life humans who cannot change as rapidly or dramatically as one can switch videos.