Thema
Journal Article
Research Support, Non-U.S. Gov't
1.454
Prospective Studies
1.170
prospective study
1.120
Studies
1.014
Research Methodology
962
Prospective study
944
prospective studies
682
Family Planning
557
Biology
553
Diseases
547
Developing Countries
484
Population
482
Demographic Factors
475
Physiology
469
Prospective studies
453
Contraception
388
Research Report
356
Population Characteristics
332
Multicenter Study
328
Research Support, N.I.H., Extramural
317
Population Dynamics
315
Developed Countries
313
Age Factors
287
Comparative Study
287
Reproduction
282
Observational Study
255
Klinische Studie
243
Randomized Controlled Trial
238
Examinations And Diagnoses
231
Americas
225
Health
225
Mortality
201
Africa
200
Treatment
197
North America
196
Measurement
194
Asia
191
Pregnancy
179
Africa South Of The Sahara
174
Biomarkers
171
Behavior
169
Contraceptive Methods
161
Northern America
153
Review
151
Laboratory Examinations And Diagnoses
149
Infections
148
Europe
145
United States
145
Contraceptives, Oral
138
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