Research on infertility: which definition should we use?

OBJECTIVE

Different definitions of infertility are used in clinical practice as well as in epidemiological and demographic research. This study assessed whether the definition makes a difference for estimates of the prevalence and sociodemographic differentials of infertility and whether one definition would be applicable in both research and clinical practice.

DESIGN

Cross-sectional study.

SETTING

Moshi town in northern Tanzania.

PATIENT(S): Community-based sample of 1,125 women, ages 20 to 44 years, in first union.

MAIN OUTCOME MEASURE(S): Six definitions of infertility.

RESULT(S): Similar levels and sociodemographic characteristics of infertile women were obtained from asking the question "How long have you tried to get pregnant?" and from secondary data collected in a birth history that included date of marriage, date of last birth, current contraceptive use, and whether the woman wants another child.

CONCLUSION(S): The infertility definition made a difference. The World Health Organization definition based on 24 months of trying to get pregnant is recommended as the definition that is useful in clinical practice and research among different disciplines.