Early Life Events Predict Adult Testicular Function; Data Derived From the Western Australian (Raine) Birth Cohort

Context: The impact of early life events on testicular function in adulthood is not well understood. Objective: To study the early influences of fetal growth, exposures to cigarette smoke in utero and cord blood estrogens, and the influences of growth and adiposity in childhood through adolescence; on testicular function in adulthood. Design: Male members of the Western Australian Pregnancy Cohort (Raine) were contacted at 20–22 years of age. Of 913 contacted, 423 (56%) agreed to participate; 404 underwent a testicular ultrasound, 365 provided a semen sample, and reproductive hormones were measured (384). Fetal growth measurements (n = 137), umbilical cord estrogen concentrations (n = 128), cord testosterone (T) (n = 125), and child-adulthood growth charts (n = 395) were available. Results: Median sperm output for the 18.6% of men exposed in utero to smoking was lower than nonexposed (82.4 × 106 vs 123.1 × 106; P = .029). Sperm output in adulthood was inversely correlated with cord serum estradiol (P = .019) and estrone (P = .018). The sperm output of men whose cord blood estradiol and estrone were less than 50th percentile vs more than 50th percentile was 191.1 × 106 vs 100.5 × 106 (P = .002) and 190.0 × 106 vs 106.0 × 106 (P = .012), respectively. Men with favorable fetal growth patterns in utero were less likely to have total motile sperm counts within the lowest quartile (P = .011), and men born prematurely had reduced serum T levels in adulthood (13.4 vs 16.6nmol/L, P = .024). Consistent height above the 50th percentile for age through childhood was associated with larger adult mean testicular volume (P < .001). Optimal body mass index trajectory through childhood and adolescence was associated with larger testicular volume (P = .009) and higher serum inhibin B (P = .010) and T (P = .003) in adulthood. Conclusions: Exposures to maternal smoking and higher cord blood estrogens at delivery were associated with a reduced sperm output in adulthood. Optimal adult testicular function depends on being born at or above average weight, and maintaining optimal growth and adiposity into adulthood. Exposure to maternal smoking and cord estrogens were negatively associated with adult sperm output. Optimal adult testicular function was related to delivery at term and optimal growth into adulthood.