Causes of Infertility — Revision Notes

⚡ 30-Second Revision

Infertility: — Inability to conceive after 12 months (or 6 months if female >35).
Primary: — Never conceived. Secondary: Conceived before, now unable.
Male Factors:

- Sperm Issues: Azoospermia (no sperm), Oligospermia (low count), Asthenozoospermia (poor motility), Teratozoospermia (abnormal morphology). - Causes: Varicocele (heat), hormonal imbalance (GnRH, FSH, LH, Testosterone), genetic (Klinefelter, Y-deletion), infections (mumps orchitis), ejaculatory dysfunction (retrograde ejaculation).

Female Factors:

- Ovulatory Disorders: PCOS (anovulation, androgen excess), Hypothalamic Amenorrhea (stress, low weight), POI (early menopause), Hyperprolactinemia (suppresses GnRH). - Tubal Factors: PID (scarring), Endometriosis (adhesions, inflammation), previous surgery. - Uterine Factors: Fibroids, Polyps, Asherman's Syndrome (intrauterine adhesions), congenital anomalies. - Cervical Factors: Stenosis, hostile mucus. - Age: Significant decline after 35.

Combined Factors: — Issues in both partners.
Unexplained Infertility: — No cause found after full workup.
Lifestyle: — Smoking, alcohol, drugs, extreme weight, stress affect both sexes.

2-Minute Revision

Infertility is defined as the failure to achieve pregnancy after 12 months of unprotected intercourse (6 months if female >35). It can be primary (never conceived) or secondary (previously conceived). Causes are broadly categorized into male, female, combined, and unexplained factors.

Male infertility often stems from issues with sperm production, function, or delivery. Common problems include low sperm count (oligospermia), poor motility (asthenozoospermia), abnormal morphology (teratozoospermia), or complete absence of sperm (azoospermia).

Conditions like varicocele (enlarged scrotal veins leading to increased temperature), hormonal imbalances (affecting FSH, LH, testosterone), genetic defects (e.g., Klinefelter syndrome), infections, and ejaculatory dysfunctions (e.

g., retrograde ejaculation) are key contributors.

Female infertility frequently involves ovulatory disorders, tubal factors, or uterine issues. Ovulatory disorders like Polycystic Ovary Syndrome (PCOS) are common, causing irregular periods and anovulation.

Other causes include premature ovarian insufficiency (early menopause) and hyperprolactinemia (suppressing ovulation). Tubal factors, such as blockages or damage from Pelvic Inflammatory Disease (PID) or endometriosis, prevent egg-sperm meeting or embryo transport.

Uterine abnormalities like fibroids, polyps, or Asherman's syndrome can impede implantation. Female age is a critical factor, with fertility declining significantly after 35. Lifestyle factors like smoking, excessive alcohol, and extreme weight negatively impact fertility in both partners.

Sometimes, despite thorough investigation, no specific cause is found, leading to a diagnosis of unexplained infertility.

5-Minute Revision

Infertility is a medical condition defined as the inability to achieve pregnancy after a year of regular, unprotected intercourse (or six months if the female is over 35). It's crucial to distinguish between primary infertility (never conceived) and secondary infertility (previously conceived but now unable). The causes are diverse and can originate from the male, female, or both partners, or remain unexplained.

Male Factors (30-40%): These primarily involve issues with sperm production, function, or delivery. Sperm abnormalities include: Azoospermia (no sperm), Oligospermia (low count, e.g., $<15 \times 10^6 \text{ sperm/mL}$), Asthenozoospermia (poor motility), and Teratozoospermia (abnormal shape). Common causes include:

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Varicocele: — Enlarged scrotal veins increase testicular temperature, impairing spermatogenesis.
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Hormonal Imbalances: — Disruptions in the Hypothalamic-Pituitary-Gonadal (HPG) axis (e.g., low FSH/LH, testosterone) affect sperm production.
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Genetic Defects: — Klinefelter syndrome (XXY) or Y-chromosome microdeletions cause testicular failure.
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Infections: — Mumps orchitis, STIs (e.g., chlamydia, gonorrhea) can damage testes or block ducts.
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Ejaculatory Dysfunction: — Retrograde ejaculation (semen into bladder), erectile dysfunction.

Female Factors (40-50%): These often involve problems with ovulation, fallopian tubes, or the uterus.

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Ovulatory Disorders: — Most common.

* PCOS: Hormonal imbalance leading to irregular periods, androgen excess, and anovulation. * Hypothalamic Amenorrhea: Due to stress, low body weight, or excessive exercise, suppressing GnRH. * Premature Ovarian Insufficiency (POI): Early loss of ovarian function before age 40. * Hyperprolactinemia: Excess prolactin suppresses GnRH, FSH, and LH, preventing ovulation.

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Tubal Factors: — Blockage or damage to fallopian tubes.

* Pelvic Inflammatory Disease (PID): Often from STIs, causing scarring and adhesions. * Endometriosis: Ectopic endometrial tissue causes inflammation, adhesions, and tubal distortion.

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Uterine Factors:

* Fibroids/Polyps: Can distort uterine cavity, interfering with implantation. * Asherman's Syndrome: Intrauterine adhesions from uterine surgery. * Congenital Anomalies: Structural defects (e.g., septate uterus).

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Cervical Factors: — Cervical stenosis (narrowing) or hostile mucus.
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Age: — Female fertility declines significantly after 35 due to reduced egg quantity and quality.

Combined Factors (10-15%): Both partners have contributing issues. Unexplained Infertility (10-15%): All standard tests are normal, but conception doesn't occur. Lifestyle factors (smoking, alcohol, drugs, extreme weight, stress) negatively impact fertility in both sexes. Diagnosis involves a thorough workup for both partners to identify the specific cause and guide appropriate treatment, which may include Assisted Reproductive Technologies (ARTs).

Prelims Revision Notes

For NEET, a strong recall of the causes of infertility is essential. Remember the definition: inability to conceive after 12 months (or 6 months if female >35) of unprotected intercourse. Distinguish between primary (never conceived) and secondary (previously conceived) infertility.

Male Factors:

Sperm Production/Quality:

* Azoospermia: No sperm. Can be obstructive (e.g., vasectomy, congenital absence of vas deferens, infection blockages) or non-obstructive (e.g., testicular failure due to Klinefelter syndrome (XXY), Y-chromosome microdeletions, cryptorchidism, mumps orchitis).

* Oligospermia: Low sperm count ($<15 \times 10^6 \text{ sperm/mL}$). * Asthenozoospermia: Poor sperm motility. * Teratozoospermia: Abnormal sperm morphology. * Varicocele: Enlarged scrotal veins $ightarrow$ increased testicular temperature $ightarrow$ impaired spermatogenesis (most common correctable cause).

Hormonal: — Hypogonadotropic hypogonadism (low GnRH, FSH, LH), hyperprolactinemia.
Sperm Transport/Delivery:

* Obstructive Azoospermia: Blockage in epididymis, vas deferens. * Ejaculatory Dysfunction: Retrograde ejaculation (into bladder), erectile dysfunction.

Female Factors:

Ovulatory Disorders (Most Common):

* PCOS: Irregular periods, hyperandrogenism, polycystic ovaries $ightarrow$ anovulation. High LH/FSH ratio. * Hypothalamic Amenorrhea: Due to stress, extreme exercise, low body weight $ightarrow$ low GnRH $ightarrow$ low FSH/LH.

* Premature Ovarian Insufficiency (POI)/Failure (POF): Ovaries stop functioning before age 40. High FSH, low estrogen. * Hyperprolactinemia: High prolactin $ightarrow$ suppresses GnRH $ightarrow$ anovulation.

* Thyroid Disorders: Hypo- or hyperthyroidism can disrupt ovulation.

Tubal Factors:

* Pelvic Inflammatory Disease (PID): Often from STIs (Chlamydia, Gonorrhea) $ightarrow$ scarring, adhesions, tubal blockage. * Endometriosis: Endometrial-like tissue outside uterus $ightarrow$ inflammation, adhesions, tubal distortion. * Previous Surgeries: Adhesions from appendectomy, C-section, ectopic pregnancy.

Uterine Factors:

* Fibroids (Leiomyomas): Benign growths distorting uterine cavity, affecting implantation. * Polyps: Endometrial growths. * Asherman's Syndrome: Intrauterine adhesions (scar tissue) from D&C. * Congenital Anomalies: Septate, bicornuate uterus.

Cervical Factors: — Cervical stenosis (narrowing), hostile cervical mucus.
Age: — Significant decline in egg quantity and quality after 35.

Other Factors:

Combined Infertility: — Both partners have issues.
Unexplained Infertility: — No cause found after full workup.
Lifestyle: — Smoking, alcohol, illicit drugs, extreme weight (obesity/underweight), stress impact fertility in both sexes.

Vyyuha Quick Recall

To remember common causes of infertility, think of 'F.A.I.L.U.R.E.S.':

Fallopian Tube Issues (PID, Endometriosis) Age (Female age >35) Immune Factors (Anti-sperm antibodies, Autoimmune conditions) Lifestyle (Smoking, Alcohol, Obesity, Stress) Uterine Problems (Fibroids, Polyps, Asherman's, Anomalies) Release of Eggs (Ovulatory Disorders: PCOS, POI, Hyperprolactinemia) Ejaculation/Erection Problems (Retrograde, ED) Sperm Issues (Azoospermia, Oligospermia, Varicocele, Genetic)