The investigators are going to select the normal child-bearing period women as the study subjects and draw their peripheral blood to observe and analyze the change of quantity and percentage of lymphocyte subsets along with the change of menstrual cycle.

Recording their BMI\menstrual history\and childbearing history, the investigators would select 300 healthy women in 6 different age groups which are aged 20-24, aged 25-29, aged 30-34, aged35-39, aged 40-44 and aged 45-49, then draw 1-2 ml blood form their peripheral vein (adding EDTA for anti-coagulation). The investigators are going to perform routine examination on the blood samples and detect T\B\NK lymphocyte through flow cytometry (FCM), thus calculating the absolute number of every species of lymphocyte. The investigators make assessment for the cellular immune function of the women during child-bearing period via comparing distinction in percentage and absolute number of every lymphocyte subset among reproductive-age women in different ages.

Inclusion Criteria:

• Women aged 20-49;
• Having a regular menstrual cycle of which the menstrual period is between day 3-7, and the period between day 25-35;
• Excluding internal and surgical disease (after having variety of physical examination such as electrocardiogram/hepatic and renal function/blood routine and urine routine).

Exclusion Criteria:

• Having experienced severe allergies, trauma history and/or operation history within 3 months;
• With a history of mental illness and/or family history of mental illness;
• Limb disabled;
• Taking medicine within one month;
• Suffering major events or having mood swings.

healthy women of child-bearing age