if this research had any truth in it then undescended testicle would be extremely common among older UK males as until perhaps 30 years ago aspirin was the most common analgesic for everyone. So statistically a great many women getting a headache or other pain or ache during pregnancy would be reaching for aspirin or aspirin based painkillers and producing large numbers of boy babies with undeescended testicles but in fact the incidence is quite low.