Idiopathic male pseudohermaphroditism is associated with prenatal growth retardation

About 50% of intersex cases are due to male pseudohermaphroditism, and of these cases, 50% are not clarified aetiologically. The association of idiopathic male pseudohermaphroditism and prenatal growth retardation has been recently reported. The aim of this study was to verify whether there was a difference in weight and/or length at birth between idiopathic and non-idiopathic male pseudohermaphroditism patients. A total of 70 patients with male pseudohermaphroditism were recruited; 35 non-idiopathic and 35 idiopathic. Birth weight and length were converted to z scores, and the severity of genital ambiguity was classified according to Prader grades: less virilized (Prader 1 to 3) and more virilized (Prader 4 or 5). Data were analysed using a Mann-Whitney test, odds ratio and logistic regression analysis. Birth weight (P = 0.028) and length (P = 0.01) z scores were lower in the idiopathic male pseudohermaphroditism group compared to the non-idiopathic group and were also significantly decreased among the less virilized patients, both in the sample as a whole (weight z score, P = 0.002; length z score, P = 0.0008) and in the group of idiopathic patients (weight z score, P = 0.013; length z score, P = 0.007). According to logistic regression analysis, only birth length z score significantly predicted the severity of the genital ambiguity in patients with idiopathic male pseudohermaphroditism ( P = 0.0007).

There is an association between prenatal growth retardation and male pseudohermaphroditism which may be due to genetic factors not clarified yet or to environmental factors which act early in gestation.