Objective: To compare maternal serum human chorionic gonadotrophin (hCG) samples before 18 weeks gestation in mothers of boys with cryptorchidism or hypospadias with that in mothers of normal boys. The effect of season on maternal hCG was also assessed.
Subjects and methods: Stored serum samples from mothers of singleton male fetuses born between January 1988 and December 1992 were assayed for total hCG, using a Delfia assay. There were 153 eligible samples from 96 mothers of normal boys, 31 of those with cryptorchidism, and 26 of those with hypospadias.
Results: The data from mothers of normal boys were used to construct a time-specific reference range for hCG. Plotting the hCG levels of the other groups and superimposing the reference range showed no significant difference between them (P = 0.09). Maternal hCG was not significantly different between cryptorchid boys requiring orchidopexy and those experiencing early spontaneous descent. An analysis of covariance allowing for gestational age showed that maternal hCG is significantly higher during the peak summer than peak winter months (P = 0.046).
Conclusion: While a seasonal effect on maternal hCG was demonstrated our data does not suggest this to be the sole cause for cryptorchidism or hypospadias or to account for the observation that both have a seasonal frequency.