Really? Never heard it before, but it could be very possible! It would be wonderful if someone could provide us with a complete list of Isabel's pregnancies, including of course those that are left. By the moment we have:
1. Isabel, 1470.
2. Miscarried son, 1475.
3. Juan, 1478.
4. Juana, 1479.
5. MarÃa and a stillborn twin sister, 1482.
6. Catalina, 1485.
7. Another miscarriage (what sex?), 1490.