Couple's infertility in relation to male smoking in a Chinese rural area.

Smoking is a well-known risk factor of reproductive health. However, the effect of paternal smoking on fertility has been less extensively examined. We conducted a cross-sectional study in a mountainous area of South-West China to assess the effect of male smoking on couples' fertility.

[The investigation and analysis of the Rh blood type distribution in four kinds of the minority nationalities (Miao, Buyi, Dong and Shui) in Guizhou, China].

Objective: To comprehend the Rh blood type distribution and the gene frequency in four main kinds of the minority nationalities in Guizhou, China, so as to supply a scientific foundation for guiding the prevention and cure against the Rh hemolysis illness.

Methods: The irrelative individual blood of the four kinds of the minority nationalities (Miao, Buyi, Dong and Shui) in Guizhou was randomly collected in complete group style and the Rh blood type was identified and analyzed.

Results: Totally 15,992 minority nationality people were inspected and checked, and 4851 persons of Han nationality people were chosen as controls.