A royal author has claimed that Kate had to take a fertility test before marrying Prince William.
This is considered a common practice for women entering the royal family, according to the author.
The author also alleges that Princess Diana was subjected to similar treatment.
Diana thought her premarital check-ups had to do with general health, but she was actually being tested for fertility.
The author's book examines the royal family's childhoods using palace staff interviews and historical data.