Research on infertility: which definition should we use?

Abstract

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.