The incidence of bilateral cryptorchidism is increased and the fertility potential is reduced in sons born to mothers who have smoked during pregnancy

PURPOSE: Recent studies have demonstrated a high prevalence of cryptorchidism, decreasing semen quality and increasing incidence of testicular cancer. These changes seem to be interrelated, and may be symptoms of a common underlying entity with foundations in fetal life. We investigated the influence of maternal smoking on fertility status in offspring cryptorchidism.

MATERIALS AND METHODS: We prospectively studied consecutive patients presenting to the pediatric surgery department between 1996 and 2005. A total of 157 boys 1 to 5.9 years old underwent surgery for cryptorchidism with simultaneous testicular biopsy, and exhibited well preserved testicular parenchyma. Only white patients with Danish-speaking mothers who had reported pregnancy history including smoking habits during pregnancy and history of the offspring were included. The patients had cryptorchidism only and none received hormonal treatment before surgery. The number of spermatogonia and gonocytes per tubule cross-section was assessed and compared to normal values from autopsy material.

RESULTS: The group of boys with cryptorchidism whose mothers had smoked heavily during pregnancy (ie more than 10 cigarettes daily throughout the pregnancy) had a significantly increased risk of bilateral cryptorchidism (52%, or 11 of 21 patients), and a decreased number of spermatogonia and gonocytes per tubule cross-section, which was absolute (0.097 [0 to 0.75]) and age related (14% [0% to 198%] of normal for age) compared to boys whose mothers did not smoke (20%, or 22 of 112 patients, 0.140 [0 to 2.14] and 37% [0% to 563%] of normal for age, p <0.01, p <0.05 and p <0.05, respectively).

CONCLUSIONS: A close relationship between maternal smoking during pregnancy and adverse trends in offspring reproductive health in relation to cryptorchidism was observed.