One of the things on my conscience concerns abortion. I have always held strict opinions about it and would opt out of being concerned in any matter to do with it. The only grounds that I could see for abortion would be if the baby had little chance of surviving the pregnancy. To ask a prenant woman with an anencephalic child to wait 9 months to deliver a baby that would die immediately seems to me too cruel to contemplate.
There was one occasion when I was faced with this. A young married woman with polycythemia was being treated by me with hydoxyurea (hydroxycarbamide). She was taking this during the first trimester of her pregnancy. She came to me worried that the baby would be affected by the carcinogenic/teratogenic drug.
Now I have always taken the view that hydroxyurea is a safe drug from this respect, and have believed that it is safe to use this drug in young people. But it is a fact that patients with polycythemia do tend to develop acute leukemia after about 13 years follow up. My opinion is that this is part of the nature of the disease rather than because of hydroxyurea since sickle cell patients who receive hydroxyurea to increase their HbF production do not develop acute leukemia. (There are only 2 cases in the literature - probably a chance encounter.)
However I could not be absolutely sure. (On one occasion a patient of mine in this situation switched from hydroxyurea to venesection when she moved to a different part of the country and promptly had a severe stroke.) In the UK it is necessary for 2 doctors to sign a form to permit the abortion to go ahead. I could have passed the buck, but it was really my decision to make, and I signed the form - the only occasion that I have.
Now there is a report in JCO (2011; 29:2410-5) which suggests that I was right all along and could have refused with a clear conscience. (Well not exactly clear, because I would also have to deal with a weeping woman who was very frightened.) The Swedish Chronic Myeloproliferative Neoplasm Study Group has reported on 11039 patients and concluded that despite a 35 fold higher risk of patients with Myeloproliferative conditions developing MDS/AML, there is no higher risk for those who have only received hydroxyurea as chemotherapy. Of course, I am talking about carcinogenicity here not teratogenicity, but they tend to go together.
This was a judgment call that I may have got wrong.