What is septicaemia?

If Savita Halappanavar’s condition was an obstetric emergency, as has been described, then her doctors were under a duty to do whatever was necessary to save her life, even if that meant sacrificing the life of the foetus.

For doctors caring for a pregnant woman, there is a pecking order and in that pecking order the life of the mother comes first. Whether or not Ireland has an abortion law, and what that law says, would be irrelevant to the case.

In most countries the unborn foetus has a different legal status – and fewer rights – than after it has been delivered as a live human being. Only then does it acquire the protection of the full gamut of the law.

But was it an obstetric emergency? Ms Halappanavar died of septicaemia, a severe infection of the bloodstream which can occur as a result of any cause from an infected toenail to a problem with a pregnancy.

She is reported to have been told that she was starting to miscarry, presumably because her waters had broken or she was bleeding.

But it is unclear whether the miscarriage caused the septicaemia or the septicaemia the miscarriage.

If her membranes ruptured early that could have allowed bacteria to ascend from her vagina into her uterus causing an infection which developed into septicaemia. Rupture of the membranes normally signals the start of labour but if there is a delay, as in this case, the risk of infection rises.

The other possibility is that she had another infection – such as of the appendix or kidney ( she complained of back pain) – and that caused the blood infection. But that is less likely.

If a woman develops an infection in her womb, that can cause a miscarriage. The infection stimulates contractions and the waters break. In that case it may be important to remove the contents of the womb, by inducing delivery of the baby, to protect the mother.

But there is a balance to be struck and sometimes mothers whose pregnancy is on the verge of viability – capable of delivering a live baby – will delay in order to give their baby a better chance. This puts them at greater risk.

Women die from septicaemia linked to pregnancy in the UK every year, and deaths – though rare - are on the increase. But they are normally at a more advanced stage of pregnancy than in Ms Halappanavar’s case.

In the UK, a woman whose membranes broke at 17 weeks would be offered a termination to avoid the risk of infection, which would be carried out by inducing labour to deliver the foetus. There would be no chance of delivering a live baby at 17 weeks.

But at 23 weeks women are given a choice of being induced immediately, with the likely death of the foetus, or help to keep them stable and delay the birth till 26 or 27 weeks when the chance of a live birth is much increased.

Many women opt to wait. But, with the removal of the barrier protecting the womb from invading bacteria following rupture of the membranes, they run the risk of infection.

If an infection occurs it can be rapid, severe, and difficult to treat – and may in rare cases be fatal.