Prostate Cancer Risk and Vasectomy. Vasectomy, a simple operation to make a man sterile, is the third-most-used form of family planning among U.S. married couples.[1] But, since 1990,conflicting scientific studies have suggested that having a vasectomy might - or might not -increase a man's risk for developing prostate cancer, the leading form of cancer among U.S. men. Because of possible risk, many urologists began to advise against vasectomy for men with a strong family history of prostate cancer. Recently, however, scientists reported that an exceptionally large study of men with vasectomies showed that they were no more likely than others to develop prostate cancer, even 25 years after the procedure. Even men whose fathers had prostate cancer were at no greater risk if they had vasectomies. The size of the study strengthens the evidence that this method of family planning is safe.

Male Contraception. For more than 30 years, scientists have worked to develop a safe, effective and reversible hormonal contraceptive for men. In a recent human trial, one dose of acyline, an antagonist of the "master" reproductive hormone, gonadotropin-releasing hormone(GnRH), temporarily halted sperm production by suppressing GnRH and testosterone secretion. Acyline was more effective and less irritating at the site of injection than previously-tested GnRH analogs. Its effectiveness and safety make acyline a strong candidate for inclusion in a male hormonal contraceptive, in combination with hormones to eliminate potentially negative effects on potency. Just as importantly, acyline could eventually help in treating otherhormone-dependent conditions including benign prostatic hypertrophy and prostate cancer, infertility, ovarian cancer, and several gynecological conditions. The research was supported through the NICHD Specialized Cooperative Centers Program in Reproduction Research.

Repeated Miscarriage and Genes. Repeated miscarriages (recurrent spontaneous abortion or RSA), without a known cause, affect one to two percent of couples who wish to have a child.[2] Women experiencing multiple miscarriages may undergo exhaustive and expensive diagnostic tests that fail to identify the cause of their miscarriages. Scientists have long assumed that a large percentage of unexplained RSAs is caused by genetic problems, but they have been unable to identify a specific gene as a cause. Recently, scientists reported that 14 to 15 percent of women with a history of unexplained RSA have a genetic flaw in one of their two X chromosomes. Also, these women are more likely to miscarry male than female fetuses. The percentage of women with the genetic aberration combined with its selective effect on male fetuses means that the flawed gene may account for up to forty percent of previously unexplained RSAs. Identifying this trait is expected to lead to blood tests to determine the risk of miscarriage in future pregnancies.

Miscarriage and an Anti-Diabetes Drug. 5 to 10 percent of U.S. women are affected by polycystic ovary syndrome (PCOS),[3] a condition that can make it difficult for a woman to become pregnant or to carry a fetus through the early months of pregnancy. Women with PCOS are three times more likely than other women to miscarry; they also have a condition, insulin resistance, that precedes diabetes. Researchers recently reported that an anti-diabetes drug, metformin, lowered the risk of a miscarriage in the first trimester of pregnancy for women with PCOS. The investigators had already demonstrated that the drug increases blood flow in the uterus and brings about changes in the uterine lining. Further research should confirm the drug's positive effects in a larger clinical trial and also evaluate its safety through the full course of pregnancy.

Preeclampsia and Insulin Resistance. Preeclampsia, a dangerous condition that complicates 3 to 4 percent of pregnancies,[4] strikes without warning and is a leading cause of maternal and fetal death. Delivery is the only known cure for preeclampsia and surviving infants are likely to have suffered a hemorrhage before birth, be small for gestational age, be premature, and have serious disorders requiring neonatal intensive care. Currently, physicians lack a reliable method of identifying women at risk for preeclampsia. Recently, however, scientists reported that women with heightened resistance to the hormone insulin in the early months of pregnancy are at risk of later developing preeclampsia. This finding suggests that physicians will be able to initiate preventive measures early in a pregnancy for women with insulin resistance. The research also implicates insulin resistance as a causative factor in preeclampsia; thus, it may ultimately be possible to prevent the condition by improving insulin sensitivity in at-risk women early in a pregnancy or even before a woman becomes pregnant.