Madam, - Patricia Casey (July 17th) writes that she wishes any debate on abortion to be honest and factual, yet her discussion of the study undertaken in New Zealand by Prof David Fergusson fails to address some of its weaknesses. The study considered confounding factors from childhood and adolescence but not factors present at the time of abortion, for example financial insecurity or relationship break-up.
More importantly, in his report Prof Fergusson admits that his study cannot differentiate between the influence of abortion and that of unwanted pregnancy on subsequent mental health.
New Zealand has a liberal abortion regime and a high abortion rate, so it is very likely that most unwanted pregnancies within the study group were terminated. It may not be informative to compare mental illness rates in women who have had abortions with those in women who have never been pregnant or have had wanted pregnancies.
A more informative comparison would be between women with unwanted pregnancies who have abortions and women with unwanted pregnancies who choose to have the baby. What would be really interesting would be to compare rates of mental illness between women who have abortions and those who are forced to continue with an unwanted pregnancy, though thankfully it seems unlikely that such a study would ever be permitted in New Zealand or elsewhere. - Yours, etc,
PAUL BROWNE, Cambridge, England.