Unexplained subfertility is defined as the failure to conceive after 12 months of unprotected intercourse without an identified cause. It accounts for approximately 15% of infertility cases. The likelihood of conception decreases with the female partner's age, with women over 36 having less than a 50% chance of pregnancy within 12 months. Initial evaluations involve counseling, history, examination, and screening tests. If no cause is found, treatments may include expectant management, medical management such as ovulation induction, or assisted reproductive techniques.

1. UNEXPLAINED
SUBFERTILITY

2. References
• NICE Clinical Guideline, Fertility problems: Assessment and
Treatment, 20 February 2013
• Unexplained subfertility: Diagnosis and Management, TOG, 14
August 2015
• Unexplained subfertility STRATOG

3. Assessments

4. •Defined as failure to achieve conception
after a 12 month attempt to conceive has
been made through unprotected vaginal
sexual intercourse.
•Diagnosis of exclusion
•Prevalence 15%, ranges between 7-21%

5. Epidemiology
• Fecundability for humans 15-20%
• Affected by age and time
• Women < 36 years old, the cumulative probability of pregnancy is
approximately 80% at 12 months of trying, and 90% by the end of 2
years.
• Women > 36 years old, less than 50% will be pregnant by 12 months.
• Graph

6. •Incidence of infertility worldwide is about 14%
• woman’s ability to conceive is affected by
duration of trying, her age and causation.
•In women under the age of 36, infertility is
defined as inability to conceive after 1 year
when no obvious causative pathology has
been identified.
•If a couple is > 36 years old, the couple should
be referred much sooner.

7. • Relative incidence of unexplained infertility depends on how
carefully other causes are investigated.
• In the UK, the incidence of ovulatory disorders is about 15%.
• Tubal disease and male factor infertility are becoming more
prevalent because of the increasing number of chlamydia
infections.
• Male factors now account for up to 40% of cases of infertility
• In about 20% of cases both male and female factors may
coexist

8. • Figure 2

9. Initial evaluation – Primary Care
• Counseling services
• Detailed history and examination
• NSAIDS use
• Update cervical smear history
• Rubella immunization history
• Screening for chlamydia
• Consider underlying conditions or systemic disease
• Provide coital and general lifestyle advice

10. Initial Evaluation – Secondary and Tertiary care
Male fertility declines with age
Recommended that serum analysis be performed at a regional dedicated
andrology lab using WHO (2010) reference values
Semen analysis
- is not an accurate test for fecundability (unless there is azoospermia or
cryptozoospermia.
- a guide for minimum standards required to obtain pregnancy in 12 months of
unprotected sexual vaginal intercourse.
- an abnormal first test warrants repeat semen analysis after 3 months
In azoospermia, crytozoospermia and severe oligozoospermia, a detailed history
should be obtained to rule out reversible causative factors.
- If a cause is found, it should be treated before repeating after 3 months
- If there is demonstrable recovery, the semen analysis should be repeated every 3
months until back to normal parameters. Couple try again for at least 6 months
before a diagnosis of unexplained infertility is made.

11. Initial Evaluation – Secondary and Tertiary care
• Tests of ovulation and ovarian reserve
• Ovarian reserve testing in tertiary care
• Woman’s age – initial predictor – ASFR
• ovarian reserve tests
• Tests of tubal patency

12. Possible aetiologies
• Subtle abnormalities in oocyte and/or sperm function
• Defective endometrial receptivity
• Subclinical endometriosis
• Nutritional factors
• Undiagnosed or untreated celiac disease
• Immunological factors
• Poor ovarian reserve can masquerade as unexplained subfertility

13. Treatment of unexplained infertility
• Treatment options
• Counseling
• Expectant management
• Medical management
• Assisted reproductive techniques (ART)