COLUMBIA, MO, May 4, 2005 ( – Scientists have determined that boys exposed to estrogen hormones in the abortifacient birth control pill while in utero are at a greater risk of developing prostate cancer and other urinary tract problems later in life.

Estrogen-like hormones deform the prostates in developing embryos, which can be a precursor to developing prostate cancer or bladder problems, according to research conducted by Frederick vom Saal of the University of Missouri in Columbia, Missouri. “These chemicals [mimic] extremely potent synthetic sex hormones, strong enough to completely control an adult women’s reproductive system,” vom Saal told New “The developing fetus is extremely sensitive to chemical disturbance…so exposing a male baby to them is a very bad idea.”

Vom Saal and his team exposed mice to ethinylestradiol, the hormone found in the birth-control pill. He found that the prostate glands had an increase in the number and size of prostate ducts and a narrowing of the bladder neck. They compared the effect of the hormone to diethylstilbestrol (DES) – a known (banned) cancer-causing agent.

As many as two million women become pregnant each year while taking the abortifacient birth-control pill, many of whom continue to take the drug for several months before realizing they are pregnant.

Contamination of urban water supplies with hormones from human waste – from the urine of women taking the pill – is another significant estrogen source. Scientists who mimicked the water quality in urban centres in rural lakes have found profound reproductive effects in aquatic life, such as male animals developing eggs in their testes, and sterilization.

In related research, it was found that fetal exposure to a synthetic estrogen analog – bisphenol A, an environmental pollutant found in polycarbonate plastics and food can liners, had similar deforming effects on the prostate.

See New Scientist coverage.