Karyotyping couples experiencing recurrent miscarriage really is worth the cost

Abstract

Sir, We read with interest the retrospective study analysing the cost–benefit of karyotyping in recurrent miscarriage.1 We are concerned that the findings of a predicted cost of between £817,280 and £1,021,600 per unbalanced pregnancy detected will lead to a reduction in the karyotyping service for those experiencing recurrent miscarriage. As stated by the authors, they have not taken into account alternative pregnancy outcomes in those couples found to have a balanced translocation after testing for recurrent miscarriage. They state that owing to the large population tested, this is unlikely to have skewed the results. However, we beg to differ—they have not factored in the potentially large proportion of those who were found to be balanced translocation carriers who subsequently avoided pregnancy, had a miscarriage before prenatal diagnosis or became pregnant but declined prenatal diagnosis. Added to this, some carrier couples may well have chosen preimplantation genetic diagnosis or opted for ovum or sperm donation, none of which will have been captured by their data. If this is the case, the figure of between £817,280 and £1,021,600 per unbalanced pregnancy detected is inaccurate. Would it not have been more prudent to calculate the cost of karyotyping based on the 406 pregnancies where a balanced translocation was found? This would produce a figure of £8052–£10,065 per balanced translocation detected, which would better reflect the yield of positive result in karyotyping for those with recurrent miscarriage. It is important also to note that the finding of a normal or abnormal karyotype would act as a prognostic indicator in further attempted pregnancies, and if karyotyping were to be restricted according to the suggestions in the article, then such information would not be available to counsel regarding prognosis in future pregnancies. We would also point out that the emotional impact of knowing a couple do not carry a chromosomal abnormality far outweighs the cost of karyotyping in such a distressing condition as recurrent miscarriage, which is well-known to be associated with anxiety and depression.2 Therefore it would be wrong to conclude that karyotyping is only valuable in those pregnancies that yield a positive result—rather it is of great benefit to have reassurance from a finding of being chromosomally normal.