If you mean aerial drones, some number more than 670,000 UAVs have been registered by the FAA. It has been estimated that something like 1 million will be flying by the New Year 2018. I guess that some 50 industries use drones with something like 30,000+ women and men learning to be commercial, etc pilots.
1 Secondary amenorrhoea is where an established menstruation has ceasedâfor three months in a woman with a history of regular cyclic bleeding, or nine months in a woman with a history of irregular periods. 2  This usually happens to women aged 40â55.
A woman is not considered to have secondary amenorrhea until she has missed three menstrual periods in a row. However, the causes of secondary amenorrhea are generally the same factors or conditions that can lead to a skipped period. If a woman is not pregnant, a missed menstrual period may be due to a wide variety of both physical and emotional conditions that range from lifestyle stress to rare and serious diseases.