Men who wear boxer shorts have higher sperm concentrations than men who wear tighter fitting underwear, according to new research published in Human Reproduction. The researchers also found that boxer shorts-wearing men had lower levels of follicle-stimulating hormone (FSH), compared to men who most frequently wore briefs, "bikinis" (very brief briefs), "jockeys" (underwear that finishes just above the knee) or other tight-fitting underwear. FSH stimulates sperm production and the researchers say that these findings suggest that it kicks into gear when it needs to compensate for testicular damage from increasing scrotal temperatures and decreasing sperm counts and concentration. The study di
IVF experts disagree about whether transferring a fresh or frozen embryo to a patient's womb offers the best opportunity for healthy babies. According to a study of almost 83,000 IVF patients published August 20 in the journal Fertility and Sterility, there is no one-size-fits-all solution. The best technique may vary, depending on how many eggs the patient produces. For a fresh transfer, patients take hormones for several weeks to stimulate egg production. Doctors retrieve the eggs, fertilize them and place one or more embryos in the mother during the same procedure. But many clinics now universally recommend freezing all embryos and waiting a few weeks for the patient to enter a new menst
A preliminary study published in the August issue of Mayo Clinic Proceedings suggests that, for some people, specific activities of gut bacteria may be responsible for their inability to lose weight, despite adherence to strict diet and exercise regimens. "We know that some people don't lose weight as effectively as others, despite reducing caloric consumption and increasing physical activity," says Purna Kashyap, M.B.B.S., a Mayo Clinic gastroenterologist and co-senior author of the study. Dr. Kashyap and his colleagues wondered if there may be other factors at work that prevented these patients from responding to traditional weight-loss strategies. "Gut bacteria have the capacity to break
