Fertility Conditions & Treatment
Understanding your diagnosis is the first step toward effective treatment. These evidence-based guides cover the four most common causes of infertility — with medically accurate information sourced from ASRM guidelines, Cochrane Reviews, and peer-reviewed literature.
All content is reviewed against published guidelines from the American Society for Reproductive Medicine (ASRM), the European Society of Human Reproduction and Embryology (ESHRE), and U.S. CDC ART surveillance data.
1 in 6 couples
experience infertility globally (WHO 2023)
40–50%
of cases involve a male factor
90%+
of infertility causes are diagnosable and treatable
40–55%
live birth rate per IVF cycle, women under 35 (SART 2022)
Common Causes of Infertility
Select a condition to read an in-depth guide covering how it affects fertility, evidence-based treatments, success rates, and questions to ask your doctor.
Polycystic Ovary Syndrome (PCOS)
Affects 1 in 10 women of reproductive age (6–12% globally)PCOS is the most common hormonal disorder in women of reproductive age — and one of the most treatable causes of ovulatory infertility.
- Leading cause of anovulatory infertility in the US
- Diagnosed by Rotterdam criteria: 2 of 3 findings (irregular cycles, hyperandrogenism, polycystic ovaries on ultrasound)
- Associated with insulin resistance in up to 70% of cases (Azziz et al., JCEM 2004)
Endometriosis
Affects ~10% of reproductive-age women; up to 50% of infertile womenEndometriosis is found in up to 50% of women investigated for infertility — and surgical plus IVF-based treatments offer real paths to parenthood even in advanced stages.
- Defined as endometrial-like tissue outside the uterus — most commonly the ovaries, fallopian tubes, and peritoneum
- Classified Stages I–IV by the American Society for Reproductive Medicine (rASRM scoring system)
- Average diagnostic delay is 7–10 years from symptom onset (Nnoaham et al., Hum Reprod 2011)
Male Factor Infertility
Contributes to 40–50% of all infertility cases; sole cause in ~20% of couplesMale factor contributes to 40–50% of all infertility cases — yet it remains underdiagnosed and undertreated despite having excellent treatment options including ICSI.
- Semen analysis is the cornerstone diagnostic test — WHO 2021 reference values define normal parameters
- Azoospermia (no sperm in ejaculate) affects 1% of all men and 10–15% of infertile men
- Varicocele is the most common correctable cause, present in ~40% of infertile men
Unexplained Infertility
Diagnosed in 15–30% of infertile couples after standard evaluationA normal fertility workup does not mean nothing is wrong — it means current tests cannot detect the specific cause, and effective treatments still exist.
- Defined as failure to conceive after ≥12 months of regular unprotected intercourse with normal standard workup
- Standard workup includes: semen analysis, ovarian reserve testing (AMH, AFC), tubal patency (HSG), and documentation of ovulation
- Potential underlying mechanisms include subtle egg quality issues, fertilization failure, implantation dysfunction, or sperm-egg interaction defects not captured by standard tests
Diminished Ovarian Reserve (DOR)
Affects approximately 10–30% of women who present for fertility evaluationDiminished ovarian reserve means fewer eggs remain than expected for your age — but it does not mean IVF is impossible, only that time matters more.
- Diagnosed by low AMH (< 1.0 ng/mL), elevated day-3 FSH (> 10 IU/L), or low antral follicle count (< 5–7 follicles)
- DOR reduces egg quantity but does not definitively predict egg quality — many women with DOR produce normal embryos
- Age is the strongest predictor of outcomes in DOR — younger women with DOR fare significantly better than older women
Premature Ovarian Insufficiency (POI)
Affects approximately 1% of women under 40; 1 in 10,000 women under 20POI — previously called premature menopause — is the loss of normal ovarian function before age 40, but pregnancy remains possible in some women.
- Defined as irregular or absent menstruation with elevated FSH (> 25 IU/L on two readings > 4 weeks apart) before age 40
- Approximately 5–10% of women with POI can still conceive spontaneously — ovarian function fluctuates intermittently
- Genetic causes (Turner syndrome, FMR1 premutation/Fragile X) account for 10–15% of POI cases
Recurrent Pregnancy Loss (RPL)
Affects 1–2% of couples; recurrence risk rises sharply after 3 or more lossesRecurrent pregnancy loss affects roughly 1–2% of couples trying to conceive — but with thorough evaluation and targeted treatment, 60–80% ultimately achieve a live birth.
- ASRM defines RPL as 2 or more failed clinical pregnancies (confirmed by ultrasound or histopathology)
- Chromosomal abnormalities in the embryo account for approximately 50% of individual miscarriages and a significant proportion of RPL
- Antiphospholipid syndrome (APS) — the most important treatable cause — is found in 5–20% of RPL patients
Adenomyosis
Estimated in 20–35% of reproductive-age women; present in up to 40% of infertile women evaluated by MRIAdenomyosis — endometrial glands growing within the uterine muscle — impairs implantation and IVF outcomes, but targeted strategies significantly improve success rates.
- Defined as endometrial glands and stroma embedded within the myometrium, causing uterine enlargement and abnormal peristalsis
- Diagnosed by transvaginal ultrasound (myometrial heterogeneity, asymmetric thickening) or MRI (junctional zone thickness > 12 mm)
- Frequently co-exists with endometriosis (20–80% overlap) and uterine fibroids
Blocked Fallopian Tubes
Tubal factor infertility accounts for 25–30% of all female infertility casesBlocked fallopian tubes prevent natural conception, but IVF bypasses the tubes entirely — and for hydrosalpinx specifically, salpingectomy before IVF dramatically improves success rates.
- Fallopian tubes can be blocked at the proximal (uterine) end, mid-segment, or distal (fimbrial) end — each with different causes and treatments
- Hydrosalpinx (fluid-filled, dilated tube) reduces IVF live birth rates by approximately 50% and must be treated before IVF
- Hysterosalpingogram (HSG) is the standard first-line screening test; laparoscopy with chromotubation remains the gold standard for diagnosis
Uterine Fibroids & Fertility
Affect up to 70–80% of women by age 50; fertility-impairing fibroids present in 5–10% of infertile womenNot all fibroids affect fertility equally — location matters more than size, and targeted treatment can restore reproductive potential in most women.
- Fibroids (leiomyomas) are classified by location: submucosal (inside the cavity), intramural (within the muscle), and subserosal (on the outer surface)
- Submucosal fibroids are the most fertility-impairing — even small ones reduce IVF implantation rates by 50–70% and must be removed
- Intramural fibroids ≥ 4 cm that distort or abut the endometrial cavity significantly reduce live birth rates
Secondary Infertility
Affects approximately 3–4 million couples in the United States; ~11% of couples who have had a prior live birthSecondary infertility — difficulty conceiving after a prior successful pregnancy — affects nearly as many couples as primary infertility and deserves the same thorough evaluation.
- Defined as the inability to conceive or carry a pregnancy to term after previously achieving a live birth
- Age-related egg quality decline is the most common cause — the interval since the last pregnancy is often the defining factor
- New-onset conditions including endometriosis, fibroids, and diminished ovarian reserve frequently develop in the interval between pregnancies
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