(HealthDay News) -- It's not unusual for a pregnant woman to begin labor up to two weeks before or after her due date.

(HealthDay News) -- Chronic obstructive pulmonary disease (COPD) is a general term for the narrowing of the small bronchi, the smaller airways that carry air to the lungs. The two prime diseases that make up COPD are chronic bronchitis and emphysema.

FRIDAY, Jan. 7 (HealthDay News) -- How doctors choose to treat their breast cancer patients -- and whether those treatment choices follow established recommendations -- may play a larger role in whether a cancer returns than experts have believed.

THURSDAY, Jan. 6 (HealthDay News) -- Among HIV-negative sexual partners, male circumcision helps prevent the transmission of human papillomavirus from men to women, according to a new study.

FRIDAY, Jan. 7 (HealthDay News) -- A new study finds that people with high levels of methicillin-resistant staphylococcus aureus (MRSA) bacteria in the nose are more likely to have other areas of the body colonized by MRSA, which can cause potentially fatal infections.

FRIDAY, Jan. 7 (HealthDay News) -- Personal motivation plays a major role in how quickly a person returns to work after a total knee replacement, new research has found.

FRIDAY, Jan. 7 (HealthDay News) -- The hand gestures you use while talking can actually shape your thoughts, a new study suggests.

FRIDAY, Jan. 7 (HealthDay News) -- Researchers have found that brain cells need to create links early in their existence, when they are physically close together, in order to ensure successful brain-wide connections throughout life.

FRIDAY, Jan. 7 (HealthDay News) -- Among Native Americans, women are more likely than men to develop eating disorders, a new study finds.

THURSDAY, Jan. 6 (HealthDay News) -- A newly published case history highlights the importance of rabies vaccinations for pets and animal shelter workers.

FRIDAY, Jan. 7 (HealthDay News) -- Making decisions about breast cancer treatment based on measures of a patient's general well-being, stress level and ability to enjoy normal life activities is most effective in clinical trials in which quality of life is the primary outcome, a new Canadian study shows.

THURSDAY, Jan. 6 (HealthDay News) -- The ability to ride a bicycle can determine whether a patient has atypical or "regular" Parkinson's disease, according to researchers in the Netherlands.

FRIDAY, Jan. 7 (HealthDay News) -- Adolescents who were breast-fed as infants have stronger leg muscles and "explosive strength" than those who were not breast-fed, a new study finds.

FRIDAY, Jan. 7 (HealthDay News) -- When you think of facial aging, wrinkles and sagging skin come to mind, but new research finds that skin isn't the only thing that ages.

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

(HealthDay News) -- Here are the latest clinical trials, courtesy of ClinicalConnection.com:

FRIDAY, Jan. 7 (HealthDay News) -- U.S. government officials said Friday that the amount of fluoride in the nation's drinking water should now be set at the lowest recommended level.

FRIDAY, Jan. 7 (HealthDay News) -- The first study to focus solely on the risk for post-traumatic stress disorder among those who survived the Sept. 11, 2001 attacks on the World Trade Center finds many afflicted by the disorder years after.