Causes and Risk Factors for Hypospadias
The cause of hypospadias is unknown but may include genetic, endocrinological, and environmental factors. Genetic factors are suggested by an increase in the condition in twins compared to a single birth. Human chorionic gonadotropin (hCG) is a hormone produced in early pregnancy that stimulates the production of estrogen and progesterone. In the case of twins, the production of hCG may not be sufficient to prevent incomplete urethral development. There is also a 20 percent chance that an infant born with hypospadias has a family member with the condition.
Endocrinological factors include low levels of androgens (e.g., testosterone, androsterone) and the infant's cells' inability to use these substances effectively may also result in hypospadias. Androgens are substances that stimulate the development of male characteristics.
Maternal exposure to increased levels of progesterone, common during in vitro fertilization (IVF), increases the risk for hypospadias in the infant.
Environmental exposure to estrogen during urethral development may also be a risk factor. Exposure can result when the mother ingests pesticides on fruits and vegetables and milk from pregnant cows.