Maternal pregnancy levels of polychlorinated biphenyls and risk of hypospadias and cryptorchidism in male offspring.
BACKGROUND
The etiologies of the male urogenital anomalies cryptorchidism and hypospadias are poorly understood. It has been suggested, however, that in utero hormone levels may be related to risk. Endocrine-disrupting chemicals, including polychlorinated biphenyl (PCB) compounds, may alter hormone levels and thereby affect the fetus.


OBJECTIVE
To examine whether in utero PCB exposure is related to cryptorchidism and hypospadias, we examined PCB levels among pregnant women enrolled in the Collaborative Perinatal Project (CPP).


METHODS
The CPP enrolled pregnant women at 12 U.S. medical centers between 1959 and 1965. For the present research, we analyzed third-trimester serum samples from the mothers of 230 sons with cryptorchidism, 201 sons with hypospadias, and 593 sons with neither condition. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression and examined the associations of each anomaly with individual PCB congener levels, sum of PCBs, and several functional groupings of PCBs.


RESULTS
In general, the ORs for cryptorchidism or hypospadias showed no notable associations with individual PCB congener levels or functional groupings of PCBs. However, the ORs and 95% CIs for the sum of PCBs associated with hypospadias were as follows: 0-1.9 microg/L, reference group; 2-2.9 microg/L, OR = 1.57, 95% CI, 1.05-2.34; 3-3.9 microg/L, OR = 1.45, 95% CI, 0.90-2.34; and > or = 4.0 microg/L, OR = 1.69, 95% CI, 1.06-2.68; p-value for trend = 0.08.


CONCLUSIONS
Given the large number of associations examined, these findings do not strongly support the hypothesis that PCBs are associated with cryptorchidism or hypospadias. Because population serum PCB levels at the time of sample collection were considerably higher than levels at present, it is unlikely that current PCB exposure is related to the development of either anomaly.
McGlynn
Katherine A
KA
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health/DHHS,6120 Executive Blvd., Rockville, MD 20852-7234, USA. mcglynnk@mail.nih.gov
Guo
Xuguang
X
Graubard
Barry I
BI
Brock
John W
JW
Klebanoff
Mark A
MA
Longnecker
Matthew P
MP
D003456:Cryptorchidism / Q000097:blood*; D005260:Female; D006801:Humans; D007021:Hypospadias / Q000097:blood*; D008297:Male; D011078:Polychlorinated Biphenyls / Q000097:blood*; D011247:Pregnancy; D012307:Risk Factors; D014481:United States
D011078:Polychlorinated Biphenyls