The Medical Council has statutory responsibility for the professional behaviour of doctors. It seeks to discharge this responsibility through the publication of guidelines on ethical issues.
The 1998 edition of A Guide to Ethical Conduct and Behaviour specifically addresses treatment of the child in utero.
Section 26.5 of the guide states: "The deliberate and intentional destruction of the unborn child is professional misconduct.
"Should a child in utero suffer or lose its life as a side effect of standard medical treatment of the mother, then this is not unethical.
"Refusal by a doctor to treat a woman with a serious illness because she is pregnant would be grounds for complaint and could be considered to be professional misconduct."
If a medical doctor has any potential concerns regarding the treatment of a pregnant woman, reference to the guidelines will quickly lead to the conclusion that he must treat her in the same way as a woman who is not pregnant.
A woman found to have a cancer while pregnant must be offered the same treatment options as the patient in the bed next to her, who is not expecting.
The full range of chemotherapy, radiotherapy and surgery will be discussed and offered to both patients.
In the case of a woman with extensive cancer of the cervix, full treatment would probably be incompatible with the ongoing viability of the foetus.
The Master of the Rotunda has made specific reference to a condition called a molar pregnancy. In this condition the womb fills with vesicles, small, usually hollow structures. Only exceptionally is there a foetus present. The diagnosis is confirmed by ultrasound examination.
Treatment involves the immediate evacuation of the womb in order to prevent severe haemorrhage. There is also a risk of the "mole" invading the wall of the uterus - doctors refer to this as a choriocarcinoma, a condition that could be life-threatening.
An ectopic pregnancy is one where the foetus develops outside the womb, usually in one of the fallopian tubes. It carries a high risk of severe haemorrhage.
Diagnosis is by laparoscopy, in which a fibre-optic telescope is passed into the abdomen. The standard treatment in the case of an ectopic pregnancy is to remove it surgically.
Elevated blood pressure can be a problem in pregnancy. The medical term for this condition is pre-eclampsia. It usually occurs in the latter stages of pregnancy and if doctors are having difficulty controlling the blood pressure using medication, then the treatment of choice is to deliver the baby early.
With modern paediatric intensive care it is now possible for a foetus as young as 24 weeks' gestation to survive.
In the rare event of severe pre-eclampsia occurring earlier than 24 weeks, it may be necessary to deliver the mother in order to save her life. While the foetus is unlikely to survive outside the womb, every effort will be made to keep it alive.
However, the primary concern must at all times be the mother's health; it is this consideration that will influence all treatment decisions in pregnancy.
Although there are many difficult ethical areas in medicine, the issue of treatment for a pregnant woman is generally not one of them.