Possible reasons for Anne Boleyn’s miscarriage?

There are all kinds of theories on this:-
- Anne Boleyn was Rhesus negative (Rh-) meaning that her body would reject all Rhesus positive babies after the first pregnancy, causing miscarriages. This is a theory put forward by Retha Warnicke to explain Anne's miscarriages following her first successful pregnancy. This would happen if Henry was Rhesus positive.
- Stress - Anne was under an incredible amount of pressure to "perform" and deliver a son. She had also had quite a difficult pregnancy with Elizabeth so I can only imagine the stress and anxiety she felt. Also her final miscarriage is thought to have happened shortly after Henry's jousting accident when he was unconscious for 2 hours and thought to be dead.
This must have been a shock for Anne. It is also said that on hearing of Catherine of Aragon's death, Anne suddenly became paranoid that she also would die and so was obviously worrying about her pregnancy and the birth.
Another stress would have been fears for her position as Henry's wife and Queen with Henry's infidelities.
- Syphilis - One theory, which has pretty much been debunked now, is that Henry had syphilis and that this venereal disease could then explain his ill health, Catherine's miscarriages, still births and infant fatalities, and Anne's miscarriages. However, Henry was not treated with mercury, the standard syphilis treatment of the time and he also did have three healthy legitimate children and at least one illegitimate child.
- Tudor times - Anne may just have been a victim of her times - A time when there was not much known about prenatal care.
- Just one of those things - Many women suffer miscarriages and Anne may just have been unlucky.
- Witchcraft, adultery and sin - Not a theory I give any credence to but people of the times believed that deformed babies, like the one that Anne was said to have lost in her final miscarriage, were due to the sexual sins of the parents. Obviously Henry didn't sin (splutter splutter!) so therefore Anne was an adulteress and witch.
- Poisoning - Some will have you believe that Anne was poisoned by the Cantrella of Borgia (secret poison) and that Wolsey, More and Seymour caused her miscarriages even though Wolsey and More were dead!

So, those are the main theories regarding Anne's miscarriages.