Infertility: Clinical Evaluation and Diagnosis

Infertility is conventionally defined as the failure to achieve a clinical pregnancy after twelve months or more of regular unprotected intercourse. Its clinical evaluation is a structured, couple-centred process that moves from definition and risk assessment through targeted history, examination, and a focused set of laboratory and imaging tests, aiming to identify ovulatory, tubal, uterine, and male factors and to recognise when no cause can be found.

Definition

Infertility is the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse (or 6 months for women aged 35 years and older, or when there is a known cause), and its clinical evaluation is the systematic assessment of both partners to identify contributing factors.

Scope

This area orients the reader to how infertility is defined and measured, how a couple is evaluated, which baseline investigations are standard, what is meant by unexplained infertility, and how findings are triaged into an initial management strategy. It gathers the diagnostic essentials as reference knowledge; it is not a protocol for treating an individual patient.

Sub-topics

• Baseline Laboratory and Imaging Investigations
• Definition, Epidemiology and Diagnostic Criteria for Infertility
• History, Physical Examination and Risk Assessment in Infertility
• Triage and Initial Management Strategy
• Unexplained Infertility

Core questions

• When does a couple meet the definition of infertility, and when should evaluation begin earlier?
• Which history, examination, and baseline tests reliably identify ovulatory, tubal, uterine, and male factors?
• What does it mean when a standard evaluation finds no abnormality (unexplained infertility)?
• How do diagnostic findings translate into an initial, evidence-based management strategy?

Key concepts

• Definition by duration of unprotected intercourse
• Couple-based (both-partner) evaluation
• Female factors: ovulatory, tubal, uterine
• Male factor and semen analysis
• Ovarian reserve
• Unexplained infertility as a diagnosis of exclusion
• Age as a dominant prognostic variable
• Triage to expectant, medical, or assisted-reproduction pathways

Mechanisms

The evaluation is built around the physiology of conception: ovulation must occur, sperm of adequate number and function must be present, the fallopian tubes must be patent to allow gamete transport and fertilisation, and the uterine cavity must permit implantation. Each standard investigation probes one of these requirements (for example, ovulation assessment, semen analysis, and tubal patency testing), so that the pattern of normal and abnormal results localises the likely barrier to conception. Where every domain tests normal, the couple is classified as having unexplained infertility.

Clinical relevance

A consistent definition and an organised evaluation allow clinicians to distinguish couples who may conceive with time from those with an identifiable barrier, and they frame the counselling around prognosis and options. As a reference area it explains how the diagnostic categories are constructed and why particular tests are used; it does not prescribe diagnosis or treatment for any individual.

Epidemiology

Infertility affects a substantial minority of couples of reproductive age. A systematic analysis of health surveys estimated that, among women of reproductive age exposed to the risk of pregnancy, a large number worldwide were affected by primary or secondary infertility, with marked regional variation (Mascarenhas et al., 2012). Female and male factors each contribute to a comparable share of cases, and a notable proportion remain unexplained after standard evaluation (Inhorn & Patrizio, 2015).

Evidence & guidelines

Definitions are harmonised in the International Glossary on Infertility and Fertility Care (Zegers-Hochschild et al., 2017) and the ASRM committee opinion on definitions (Practice Committee, 2020). Evaluation pathways are set out in the ASRM committee opinion on diagnostic evaluation of the infertile female (Practice Committee, 2015) and in national guidance such as NICE CG156 (2013, updated 2017).

History

Systematic infertility evaluation developed through the twentieth century as endocrine assays, semen analysis, and tubal imaging matured, and as assisted reproductive technologies created a need for consistent diagnostic categories. International standardisation of terminology, culminating in successive editions of the ICMART/WHO glossary, gave the field a shared vocabulary for definition and diagnosis (Zegers-Hochschild et al., 2017).

Debates

When should evaluation and treatment begin?

Guidelines support earlier evaluation for women aged 35 and older or where a cause is suspected, but the optimal threshold balances avoiding delay against over-investigating couples who would conceive spontaneously.

Seminal works

• zegers-hochschild-2017
• practice-committee-asrm-2015-female
• mascarenhas-2012

Frequently asked questions

How long should a couple try before seeking evaluation?

Infertility is conventionally defined after 12 months of regular unprotected intercourse, but earlier evaluation is generally recommended for women aged 35 and older or when there is a known reason to suspect a problem.

Is infertility a female problem?

No. Evaluation is couple-based, and female factors, male factors, combined factors, and unexplained infertility each account for a meaningful share of cases.