Thema
Retrospective Studies
Journal Article
61
Demographic Factors
59
Population
59
Studies
59
Research Methodology
56
Age Factors
54
Population Characteristics
54
Adolescents
47
Youth
46
Developed Countries
39
Adolescents, Female
36
Americas
35
Population Dynamics
35
Fertility
34
North America
33
Adolescent Pregnancy
32
Reproductive Behavior
32
Northern America
30
Research Report
30
United States
29
Family Planning
28
Adolescent
25
Contraception
23
Female
22
Male
22
Developing Countries
21
Diseases
19
Adult
18
Child
18
Reproduction
18
Behavior
17
Biology
17
Health
16
Pregnancy
16
Comparative Study
14
Delivery Of Health Care
14
Human
13
Medicine
13
Physiology
13
R
13
Sex Behavior
13
Contraceptive Usage
12
Ethnic Groups
12
Comparative Studies
11
Economic Factors
11
Humans
11
Research Support, Non-U.S. Gov't
11
Cultural Background
10
Health Services
10
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