Chinese developing birth control for men

BEIJING, May 4 (UPI) -- A study in China suggests testosterone shots for men may aid in birth control, researchers in Bejing said.

In the largest study of its kind, 1,045 fertile Chinese men between the ages of 20 and 45 received testosterone injections for two years, The Daily Telegraph reported Monday.

All of the men had fathered at least one child within the previous two years and none of their partners had fertility problems.

The trial showed a 99 percent success rate at preventing pregnancy and all but two of the men had their fertility levels return to normal at the end of the study, said Yi-Qun Gu, a doctor at the National Research Institute for Family Planning in Beijing.

"For couples who can not, or prefer not to use only female-oriented contraception, options have been limited to vasectomy, condom and withdrawal," Yi-Qun said.

Larger tests are needed to determine the long-term effects of testosterone injections on men's hearts and prostate glands, Yi-Qun said.