Association of In Utero Exposure to Maternal Smoking with Reduced Semen Quality and Testis Size in Adulthood: A Cross-Sectional Study of 1,770 Young Men from the General Population in Five European Countries

Abstract

Between 1996 and 1999, the authors invited all young men from five European countries who were undergoing compulsory medical examination for possible military service to participate in a study on male reproductive health. The participation rate was 19% in two cities in Denmark (n = 889), 17% in Oslo, Norway (n = 221), 13% in Turku, Finland (n = 313), 14% in Kaunas, Lithuania (n = 157), and 19% in Tartu, Estonia (n = 190). Each man provided a semen sample, was examined by a physician, and, in collaboration with his mother, completed a questionnaire about general and reproductive health, current smoking habits, and exposure to smoking in utero. After adjustment for confounding factors, men exposed to smoking in utero had a reduction in sperm concentration of 20.1% (95% confidence interval (CI): 6.8, 33.5) and a reduction in total sperm count of 24.5% (95% CI: 9.5, 39.5) in comparison with unexposed men. Percentages of motile and morphologically normal sperm cells were 1.85 (95% CI: 0.46, 3.23) and 0.64 (95% CI: -0.02, 1.30) percentage points lower, respectively, among men exposed in utero, and exposed men had a 1.15-ml (95% CI: 0.66, 1.64) smaller testis size. The associations were present when data from the study centers were analyzed separately (though not in Lithuania, where only 1% of mothers smoked during pregnancy), although the strength of the association varied. Maternal smoking may have long-term implications for the reproductive health of the offspring. This is another good reason to advise pregnant women to avoid smoking.

Male reproductive organs are at risk from environmental hazards

“…The fact that fetal exposure may indeed be important is demonstrated by several Danish studies that now consistently indicate that mothers' tobacco smoking during pregnancy is related to rather strong reduction in sperm counts in male offspring. It also seems that fetal exposure to tobacco smoking has stronger impact on semen quality than smoking during adult age [49][50][51][52][53]. Studies of twins, half and full siblings also indicate that early exposures taking place in-utero are important in causing cryptorchidism [54].…”

The male biological clock is ticking: a review of the literature

“…For instance, 20% of the individuals in population-based studies are typically recruited among young men willing to provide semen samples. 7 thus constituting an inevitable participation bias in such studies. 8,9 In addition, mostly of the published studies on sperm output among older men are largely restricted to patients attending infertility clinics, where few are more than 50 years old.…”

Testicular Dysgenesis Syndrome: Pathogenesis and Clinical Consequences

“…Opisywano zahamowanie wydzielania testosteronu, hiperplazję komórek Leydiga, obecność tych komórek wewnątrz kanalików plemnikotwórczych, wystę-powanie wielojądrzastych gonocytów i kanalików z niedojrzałymi komórkami Sertoliego oraz opóźnie-nie różnicowania komórek okołokanalikowych. Innymi czynnikami, które mogą zaburzać rozwój jąder w okresie płodowym, są wewnątrzmaciczne zahamowanie wzrostu płodu, wcześniactwo, palenie papierosów przez matkę w okresie ciąży [31,32].…”