The sex ratio of offspring of women with congenital adrenal hyperplasia

Abstract

Sir, We have with great interest read the comments made by Dr James concerning our paper ‘Fertility and pregnancy outcome in women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency’ recently published in Human Reproduction (Hagenfeldt et al., 2008). We have also enjoyed reading some of his extensive work in the area concerning sex ratio in mammals. We appreciate that Dr James is confirming the data we presented in our paper on the sex of children born to women with congenital adrenal hyperplasia (CAH). In addition to the data given in Table 1 in Dr James’ comments, another 22 girls and 11 boys were reported by Lo and Grumbach (2001). Hence, including our own data, the number so far reported in the literature (apart from cases that are reported twice) are 68 girls and 34 boys (sex ratio 0.33). Dr James proposes that the reason for this difference in sex ratio of children born to women with CAH could be depressed androgen levels in the women at conception. This is an interesting hypothesis and seems reasonable since most women with CAH need to have depressed androgen levels in order to ovulate regularly. Concerning the effect of gonadotrophin stimulation, only one of our patients needed this treatment; she delivered one girl after each of these treatments. As far as we know the sex ratio in women who underwent IVF is normal. In our material, only one woman needed IVF. We are looking forward to a future discussion concerning the possible explanation to the unequal sex ratio in children born to CAH women.