Cryptorchidism and maternal alcohol consumption during pregnancy

Abstract

Background: Prenatal exposure to alcohol can adversely affect the fetus. We investigated the association between maternal alcohol consumption during pregnancy and cryptorchidism (undescended testis) among newborn boys.

Methods: We examined 2,496 boys in a prospective Danish-Finnish birth cohort study for cryptorchidism at birth (cryptorchid/healthy: 128/2,368) and at 3 months of age (33/2,215). Quantitative information on alcohol consumption (average weekly consumption of wine, beer, and spirits and number of binge episodes), smoking, and caffeine intake was obtained by questionnaire and/or interview once during the third trimester of pregnancy, before the outcome of the pregnancy was known. For a subgroup (n = 465), information on alcohol consumption was obtained twice during pregnancy by interviews.

Results: We investigated maternal alcohol consumption both as a continuous variable and categorized. The odds for cryptorchidism increased with increasing weekly alcohol consumption. After adjustment for confounders (country, smoking, caffeine intake, binge episodes, social class, maternal age, parity, maturity, and birth weight) the odds remained significant for women with a weekly consumption of five or more alcoholic drinks (odds ratio = 3.10; 95% confidence interval, 1.05-9.10).

Conclusions: Regular alcohol intake during pregnancy appears to increase the risk of congenital cryptorchidism in boys. The mechanisms for this association are unknown. Counseling of pregnant women with regard to alcohol consumption should also consider this new finding.

Figure 1

Flow chart of the total number of women included in early pregnancy in a joint Danish–Finnish birth cohort study, and numbers of dropouts during follow-up before and after birth. ^aSex of child unknown. ^bDenmark: 4 moved, 44 uninterested, 3 child deaths, 7 child sickness, 17 lost, 7 other reasons; Finland: 13 lost. ^cDenmark: including 5 pairs of male–male twins; Finland: including 1 pair of male–male twins. ^dDenmark: 1 unilateral torsion, 1 could not be classified for the position of the testes at birth due to severe bilateral inguinal hernia, and 1 not classified at birth; Finland: 1 unilateral agenesis testis. ^eDenmark: 45 twins including 13 pairs of male–male twins; Finland: 20 twins including 8 pairs of male–male twins.