Risk factors for cryptorchidism: a nested case-control study

Maternal smoking, alcohol consumption, and caffeine consumption during pregnancy in relation to a son's risk of persistent cryptorchidism: a prospective study in the Child Health and Development Studies cohort, 1959-1967

The Child Health and Development Studies is a > or =40-year follow-up of 20,754 pregnancies occurring between 1959 and 1967 in California. There were 84 cases of undescended testes at birth persisting to at least age 2 years among 7,574 liveborn sons whose mothers were interviewed in early pregnancy. Cases were matched to three controls on birth year and race. Compared with mothers of controls, mothers of cryptorchid boys consumed more caffeine during pregnancy (odds ratio = 1.4, 95% confidence interval: 1.1, 1.9 for an interquartile range equivalent to three cups of coffee per day) but were not more likely to smoke or drink alcohol when all behaviors were considered together. Other maternal and perinatal risk factors were not significantly associated with persistent cryptorchidism and did not confound the association with caffeine.

Maternal smoking and undescended testes: reaching a tipping point

In this issue, Jensen et al (Epidemiology. 2007;18:220-225) publish new evidence linking maternal smoking with cryptorchidism. These new data make the cumulative evidence for a true association persuasive enough to be seriously considered. Possible biologic mechanisms may include endocrine disruption by cigarette smoke, although the role of endocrine disruptors in cryptorchidism more generally has been inconsistent. There are important research questions suggested by the link between mother's smoking and cryptorchidism, including a possible role of father's smoking, the role of genetic susceptibility, and the effects of mother's smoking on further aspects of her son's reproductive health.

Cryptorchidism according to maternal gestational smoking

BACKGROUND

It has been suggested that maternal smoking during pregnancy is a risk factor for low sperm counts and testicular cancer in the offspring. Cryptorchidism is associated with both of these disorders and might share causal mechanisms.

METHODS

We used prospective information on prenatal exposures and obstetric information on the birth of 5716 boys, collected from 1984 to 1987. During the 16-19 years of follow-up, 270 cases of cryptorchidism were diagnosed, and 185 of these boys underwent orchiopexy.

RESULTS

Compared with nonsmokers, the adjusted risk ratio for being diagnosed with cryptorchidism was 1.1 (95% confidence interval = 0.8-1.6) if the mothers smoked 10-19 cigarettes/day and 2.3 (1.1-5.0) if they smoked > or = 20 cigarettes/day. The risk ratios for orchiopexy were 1.4 (0.9-2.1) and 1.8 (0.6-5.0), respectively.

CONCLUSION

An excess risk of cryptorchidism was observed among sons of mothers who smoked 10 cigarettes or more per day during pregnancy. In recognition of the limited power of this study, the findings should be replicated in larger cohorts.

Cryptorchidism and maternal alcohol consumption during pregnancy

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.

Maternal Smoking and Testicular Germ Cell Tumors

Testicular germ cell tumors (TGCT) are the most common cancer among men ages 15 to 35 years in the United States. The well-established TGCT risk factors cryptorchism, prior diagnosis of TGCT, and family history of testicular cancer indicate that exposures in early life and/or in the familial setting may be critical to determining risk. Previous reports of familial clustering of lung cancer in mothers and testicular cancers in sons suggest that passive smoking in childhood may be such an exposure. To clarify the relationship of passive smoking exposure to TGCT risk, data from 754 cases and 928 controls enrolled in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants study were analyzed. Data from 1,086 mothers of the cases and controls were also examined. Overall, there was no relationship between maternal [odds ratio (OR), 1.1; 95% confidence interval (95% CI), 0.9-1.3] or paternal smoking (OR, 1.0; 95% CI, 0.8-1.3) and TGCT risk. Although living with a non-parent smoker was marginally related to risk (OR, 1.4; 95% CI, 1.0-2.1), there was no relationship with number of smokers, amount smoked, or duration of smoking. Responses from both case-control participants and mothers also revealed no relationship between either maternal smoking while pregnant or while breast-feeding. Results did not differ by TGCT histology (seminoma, non-seminoma). These results do not support the hypothesis that passive smoking, either in utero or in childhood, is related to risk of TGCT. Other early life exposures, however, may explain the familial clustering of lung cancer in mothers and TGCT in sons.

Maternal serum alpha-fetoprotein level during pregnancy and isolated cryptorchidism in male offspring

Cryptorchidism is thought to result from a disruption of the androgen-estrogen balance in utero. Alpha-fetoprotein (AFP) interacts with and may modulate fetal responses to estrogens. Using a cohort of boys born to women participating in a Danish maternal serum AFP screening program between 1980 and 1994, the authors explored whether AFP levels (as reflected by maternal serum AFP levels in gestational weeks 14-22) were associated with the risk of isolated cryptorchidism in male offspring. Cryptorchidism diagnoses and covariate information were obtained from Denmark's national health registries. Risk ratios for cryptorchidism by maternal serum AFP multiples of the median were estimated by use of log-linear binomial regression. Of 25,418 boys, 663 (2.6%) were diagnosed with cryptorchidism. After adjustment for confounders, boys with maternal serum AFP levels greater than or equal to 2.5 times the median had a 63% (95% confidence interval: -2, 172) greater risk of cryptorchidism than did boys with maternal serum AFP levels within 25% of the median. High fetal AFP levels may contribute directly to events producing cryptorchidism; alternatively, elevated maternal serum AFP levels may reflect placental dysfunction, some aspect of which contributes to cryptorchidism.

Laparoscopic Orchiopexy for Palpable Undescended Testes: A Five-Year Experience

BACKGROUND

Most recent reports of laparoscopic orchiopexy concern nonpalpable testes. We report the results of this approach in patients with undescended palpable testes.

MATERIALS AND METHODS

Between January 1999 and September 2004, 28 patients with 30 undescended palpable testes were treated by laparoscopic orchiopexy performed by the same surgeon. Patients with palpable cryptorchidism were included. Patients with nonpalpable testes, retractable, or vanishing testes were excluded. The mean age of the patients was 25 months (range, 8 months-5 years) and the mean weight was 16 kg (range, 8-24 kg). We used a 4-port technique (one 10-mm, two 2-3 mm, and one 5-mm), a 4-mm scope, and 2-3 mm instruments.

RESULTS

The mean operative time was 50 minutes. The complication rate was 13.3% (4/28), all in the first two years, at the beginning of the learning curve. The remaining testes were descended by laparoscopy; 5 (16.6%) were peeping testes. We had 10 (33.3%) left and 16 (53.3%) right palpable cryptorchidia cases, plus 4 testes (13.3%) that were bilateral undescended and palpable. No hernia was found in 8 (28.6%) cases; a homolateral hernia was found in 18 (64.3%) cases, and we did not close the processus vaginalis, we only resected the membranes. We found 2 (7.1%) with contralateral hernia in which we did close the processus vaginalis. On follow-up ranging 5 months-5 years, 29 of these testes maintain good size and a correct position, with no recurrent inguinal hernia.

CONCLUSION

The laparoscopic approach is a safe way to descend the palpable testicle. Although this is not a large series, it shows that laparoscopic orchiopexy of palpable undescended testes can be done without a higher complication rate than the open procedure (13.3% vs. 12.2%), with several of the advantages of the laparoscopic approach.

The CAG repeat within the androgen receptor gene and its relationship to cryptorchidism

PURPOSE

We examined the significance of the CAG repeat polymorphism in the pathogenesis of cryptorchidism.

MATERIALS AND METHODS

Genomic deoxyribonucleic acid (DNA) was extracted from blood samples from 42 cryptorchid boys and from 31 non-cryptorchid control subjects. In the cryptorchid group, 7 had bilateral cryptorchidism and 6 had patent processus vaginalis in the contralateral side. To determine the number of CAG repeats, the DNA was amplified by polymerase chain reaction and sequenced.

RESULTS

The mean CAG repeat length in the AR gene was 22.5 (range 16 to 28) in patients and 21.5 (range 17 to 26) in controls (non-significant). Patients with bilateral cryptorchidism had a mean length of 24.3 (range 21 to 26) and patients with unilateral cryptorchidism and patent processus vaginalis in the contra lateral side had a mean of 25.2 (range 21 to 28), which was statistically different from controls (p = 0.015 and p = 0.005 respectively).

CONCLUSION

CAG repeat length of the AR gene does not seem to play a major role in patients with unilateral cryptorchidism. However, in patients with bilateral undescended testis, a less functional androgen receptor through a longer polyglutamine chain may have a role in its pathogenesis. In the same way, patients with unilateral cryptorchidism a contralateral patent processus vaginalis have longer CAG repeats that might be responsible for a slower testicular descent and incomplete closure of the processus vaginalis.

Low Birth Weight and Male Reproductive Function

Scientific interest in morbidity in children born small for gestational age (SGA) has increased considerably over the last few decades. The elevated risk of cardiovascular and metabolic diseases in adulthood in individuals born SGA has been well documented, whereas data on gonadal development are limited. Prospective studies, case-control investigations and registry surveys show that impaired intrauterine growth increases the risks of congenital hypospadias, cryptorchidism and testicular cancer approximately two- to threefold. Although few studies focus on the effect of intrauterine growth on male pubertal development, testicular hormone production or sperm quality, available evidence points towards a subtle impairment of both Sertoli cell and Leydig cell function. Animal studies support the hypothesis that impaired perinatal growth restriction, depending on the timing, can affect postnatal testis size and function into adulthood. Current human data, however, are often based on highly selected hospital populations and lack precise distinctions between low birth weight, SGA, timing of growth restriction and a differentiation of catch-up growth patterns. Despite the methodological inadequacies of individual study results, the combined evidence from all data leaves little doubt that fetal growth restriction is associated with increased risk of male reproductive health problems, including hypospadias, cryptorchidism and testicular cancer.

Cryptorchidism: diagnosis, treatment, and long-term prognosis

Cryptorchidism is a common anomaly treated by every pediatric urologist. The etiology is multifactorial and includes hormonal and molecular factors. Diagnostic abilities may be enhanced by radiologic advances. Hormonal and surgical treatment modalities are discussed herein, as well as the identification and prevention of long-term sequelae.

Incidence at birth and natural history of cryptorchidism: a study of 10,730 consecutive male infants

Of the 10,730 neonates born in the period 1978-1997 and examined for cryptorchidism (C) at birth, 1387 were pre-term (gestational age <37 wk), and 9343 were full-term. At birth, a total of 737 neonates (6.9%) were cryptorchid, 487 had bilateral C and 250 unilateral C. The C rate of pre-terms was 10 times higher than that of the full-terms (30.1 and 3.4%, respectively). Comparing the two studied decades, a significant decrease of C rate was found in the second decade in full-term neonates. The rates of C at birth were significantly elevated for low birth weight, babies born from mothers with an age <20 or >35 yr, newborns from mothers with A Rh positive and B Rh positive blood group. Of the 737 cryptorchid newborns at birth, 613 (83%) were re-examined after 12 months from the expected date of delivery, and those born in the period 1988-1997 were also re-evaluated at 6 months of life. Late spontaneous descent occurred in 464 cases (75.7%), while 149 (24.3%) were still cryptorchid. The incidence of C at 12 months from the expected date of delivery, after survival curve calculation, in term and pre-term infants, was 1.53 and 7.31%, respectively, in the period 1978-1987, and 1.22 and 3.13% respectively, in the 2nd decade (1988-1997). In the groups also examined at 6 months of life, spontaneous descent occurred almost completely within the first 6 months of life in term infants, but not in pre-terms. No evidence of seasonal cyclicity was found. Medical and/or surgical treatment was generally started within 2-4 yr of age earlier in the second decade of the study. In conclusion, the main risk factor for C at birth and at 12 months of life seems to be pre-term birth and low birth weight. If this is associated itself to a higher risk of infertility too, it remains to be defined.

Maternal, delivery, and perinatal characteristics associated with cryptorchidism: a population-based case-control study among births in Washington State

BACKGROUND

The etiology of cryptorchidism is largely unknown. To identify maternal, perinatal, and delivery characteristics associated with cryptorchidism at birth, we conducted a population-based case-control study using Washington State birth certificates linked to birth hospitalization records.

METHODS

We identified 2,395 cases of cryptorchidism among male infants born in Washington State during 1986-1996, and, for comparison, we randomly selected four controls per case (N = 9,580), frequency-matched by year of birth.

RESULTS

Infant characteristics associated with cryptorchidism included low birth weight (OR = 1.5; 95% CI = 1.3-1.8), small size for gestational age (OR = 1.9; 95% CI = 1.6-2.2), and breech presentation (OR = 1.7; 95% CI = 1.4-2.1). In addition to cryptorchidism, cases were more likely to have another type of congenital malformation (OR = 3.7; 95% CI = 3.2-4.2), particularly digestive (OR = 6.8; 95% CI = 3.7-12.7) or genitourinary (OR = 4.1; 95% CI = 3.0-5.6). Maternal and pregnancy characteristics associated with cryptorchidism included nulliparity (OR = 1.2; 95% CI = 1.1-1.3), maternal smoking during pregnancy (OR = 1.2; 95% CI = 1.1-1.4), and the following pregnancy complications: oligohydramnios (OR = 1.8; 95% CI = 1.3-2.6), placental abnormality (OR = 1.3; 95% CI = 1.0-1.8), and pregnancy-induced hypertension (OR = 1.6; 95% CI = 1.4-1.9). Odds ratios were similar when the analysis was restricted to term infants.

CONCLUSIONS

These findings suggest that factors affecting fetal growth and development may increase the risk of cryptorchidism.

Prevalence and characteristics of cryptorchidism in a Nigerian district

OBJECTIVE

To determine the prevalence and characteristics of cryptorchidism among primary schoolboys in a Nigerian district.

SUBJECTS AND METHODS

The district selected had 35 primary schools with 23,342 pupils, consisting of 11,275 girls and 11,967 boys. Using a cluster-sampling technique, five primary schools were visited; 1096 boys (aged 5-13 years) participated in the study, giving a sampling ratio of 1:11. The boys underwent a clinical examination of the groin, scrotum and abdomen.

RESULTS

Cryptorchidism was found in nine subjects, giving a prevalence rate of 0.82%. All the undescended testes were unilateral, of which five were right-sided. Eight of the testes were intracanalicular and one was at the external ring. There were no cases of orchidopexy.

CONCLUSION

The prevalence of cryptorchidism among primary schoolboys in this district of Nigeria was high, at eight per 1000. Delayed diagnosis and treatment remains a problem because of the prevailing socio-economic factors. However, the incidence of cryptorchidism was similar to that reported in other parts of the world.

Postmarketing surveillance of medications and pregnancy outcomes: clarithromycin and birth malformations

PURPOSE

This retrospective surveillance study used linked administrative claims data and medical records to determine the rate and types of birth malformations in infants born to women exposed to the antibiotic, clarithromycin (Biaxin), during the first trimester of pregnancy.

METHODS

Pharmacy and hospital claims from eight geographically diverse health plans were used to identify women who had a delivery claim within 270 days of a clarithromycin prescription over a 5-year period (1991-1995). Hospital delivery admission medical records for 143 mothers and their 149 infants were abstracted to identify birth malformations.

RESULTS

Five infants were identified with major malformations, three with minor malformations, and four with undescended testicles likely to resolve with time. The observed rate of 3.4% (95% CI, 0.5, 6.3) for major malformations was not statistically significantly different compared to an expected rate of 2.8% based on earlier national data. There was no consistency across types of major malformations.

CONCLUSIONS

These results provide no evidence that clarithromycin is a likely major teratogen in humans. Use of claims data is one way to evaluate quickly and efficiently the safety of prescription medications in humans during pregnancy, especially when both exposure and outcome are rare.

Male reproductive health: cause for concern?

A substantial body of evidence has accumulated in recent years that human semen quality may be deteriorating. This has been associated with evidence of other changes in male reproductive health, including increases in congenital malformations and testicular cancer in humans, and similar problems in wildlife. Unfortunately, the evidence remains inconclusive. It has been suggested that these changes may be due to environmental xeno-oestrogens acting during development. Although there is now a large quantity of data indicating that this is a plausible hypothesis, evidence of causality, rather than association, remains to be provided. The potential importance of these changes for human health is considerable and urgent research is required to clarify the situation.