I was surprised to learn of other European royal women who underwent numerous pregnancies, none of which resulting in a surviving child. Consider Infanta Adelgundes of Portugal (1858-1946), fifth child and fourth daughter of Dom Miguel I. She became the second wife of Prince Enrico of Bourbon-Parma, Count of Bardi -- but didn't have any more success in giving her husband any children than his first wife (who died only 3 months after the marriage). All 9 of her pregnancies ended in miscarriage.
Queen Carola of Saxony (consort of King Albrecht) also underwent numerous pregnancies (10) which all ended in miscarriage. That was the main reason that the throne of the kingdom eventually passed to her brother-in-law, who succeeded as King Georg (father of Friedrich Augustus III, who would become the last king).
Any other notable examples? I would imagine that Queen Anne holds the record.