Fertility: prenatal tobacco exposure associated with an increased risk of oligozoospermia in adulthood risk

Exposure to tobacco in utero is associated with an almost doubled risk of oligozoospermia in adulthood, the risk being dependent on the exposure dose, according to a published in the journal "Human Reproduction" Danish study.
Previous studies have suggested a lower concentration of sperm in men exposed in utero to tobacco and a lower fertility.

Mr. S. Jensen and colleagues from Aarhus University Hospital wanted to deepen the research and also examine the possible dependence of this association to the exposure dose.

For this, they analyzed the sperm of 945 men who provided information on their reproductive factors and lifestyle. The researchers also collected data on maternal smoking habits during pregnancy among 522 mothers of participants.

The risk of oligozoospermia, defined by a sperm concentration less than or equal to 20 million / ml, was 2.6 times in men exposed in utero to more than 10 cigarettes per day. The risk for those exposed to less than 10 cigarettes per day was multiplied by 1.5, but not significant.

For all men exposed compared with unexposed, the risk was multiplied by 1.8.

The authors also found a nonsignificant trend toward a decrease in sperm concentration in a dose-dependent: it was 65 million / ml in men unexposed 59.1 million / ml in those exposed to less than 10 cigarettes / day and 57.7 million / ml in those exposed to more than 10 cigarettes per day.

"In our opinion, these data support the hypothesis that maternal smoking during pregnancy is associated with lower spermatogenic capacity in the son in adulthood, although the establishment of a causal link is still premature to say, "the authors conclude.