Quick Answer
Infertility contributes 2–3 NEET PG questions per paper, spanning OBG, Endocrinology, and Forensic Medicine (ART regulations). The high-yield framework:
- Definition — 12 months of unprotected intercourse without conception (6 months if female age ≥35).
- Workup couple-based — semen analysis first (cheap, non-invasive), then ovulation, tubal patency, ovarian reserve.
- Causes split — male factor 30–40%, ovulatory 25%, tubal 15%, unexplained 10–15%, combined 20%.
- PCOS — Rotterdam criteria (2 of 3: oligo/anovulation, hyperandrogenism, polycystic ovaries on USG).
- First-line ovulation induction — letrozole (replaced clomiphene per PPCOS II).
- ART ladder — IUI → IVF → ICSI for severe male factor.
- Indian regulation — ART Act 2021 + Surrogacy Act 2021; commercial surrogacy banned.
Infertility is one of the most clinically rich and frequently tested OBG topics on NEET PG 2026. Beyond the workup algorithm, examiners are increasingly testing knowledge of WHO 2021 semen reference values, the shift to letrozole as first-line ovulation induction, the structure of an IVF cycle, and the legal framework introduced by India's ART (Regulation) Act 2021 and Surrogacy (Regulation) Act 2021. Vignettes typically blend a couple's history with one or two key lab results and ask the next best step.
This NEETPGAI ultimate guide consolidates the evidence-based infertility curriculum into the diagnostic algorithm, the must-know investigations, the medical and surgical treatment pathways, the ART ladder, and the regulatory pearls that are distinctively examined in Indian postgraduate entrance tests. Pair it with focused practice on the OBG subject hub and the PCOS comprehensive guide for full reproductive endocrinology mastery.
Definition and epidemiology
Infertility is the inability to conceive after 12 months of regular unprotected intercourse in women aged under 35 years, or 6 months in women aged 35 years or older. Prevalence in India is approximately 10–15% of couples of reproductive age — a major public health concern that drives the volume of ART clinics and, in turn, the regulatory framework you are expected to know.
- Primary infertility: no prior conception.
- Secondary infertility: prior pregnancy (regardless of outcome) but unable to conceive again.
- Fecundability: probability of conception per cycle (~20–25% in normal couples).
- Cumulative pregnancy rate at 12 months: ~85% in healthy couples; falls sharply after age 35.
Earlier workup is warranted with known risk factors: age over 35, oligomenorrhea, prior pelvic surgery, history of PID or STI, suspected endometriosis, undescended testes, prior chemotherapy or radiotherapy.
Causes — couple-based etiology
Infertility is a couple problem, not a women's problem. Standard distribution:
| Cause | Frequency |
|---|
| Male factor | 30–40% |
| Ovulatory dysfunction | 25% |
| Tubal/peritoneal factors | 15% |
| Unexplained | 10–15% |
| Combined | 20% |
| Cervical / uterine | <5% |
The single most common identifiable cause overall is male factor, which is why semen analysis is the first investigation in any infertility workup.
Male factor evaluation
History and examination
- Sexual history: erectile or ejaculatory dysfunction, frequency, lubricants (some are spermicidal).
- Past surgery: orchidopexy, herniorrhaphy, vasectomy reversal.
- Drug history: anabolic steroids (suppress LH/FSH), chemotherapy, sulfasalazine, ketoconazole, calcium channel blockers, opioids.
- Examination: testicular size and consistency (Prader orchidometer; normal >15 mL), varicocele (left-sided, "bag of worms"), absent vas deferens (CBAVD — think CFTR mutations).
Semen analysis (WHO 2021 lower reference limits)
| Parameter | Lower limit |
|---|
| Volume | ≥1.4 mL |
| Sperm concentration | ≥16 million/mL |
| Total sperm count | ≥39 million/ejaculate |
| Total motility | ≥42% |
| Progressive motility | ≥30% |
| Normal morphology (strict Kruger) | ≥4% |
| Vitality | ≥54% |
| pH | ≥7.2 |
Pre-test instruction: 2–7 days of abstinence; collect by masturbation into a sterile container; analyse within 1 hour. Always repeat abnormal results after 2–3 weeks before labeling as abnormal.
Terminology to memorise
- Azoospermia — no sperm. Obstructive (normal FSH, normal testes, absent vas) vs non-obstructive (high FSH, small testes).
- Oligozoospermia — count below reference.
- Asthenozoospermia — reduced motility.
- Teratozoospermia — reduced normal forms.
- Oligoasthenoteratozoospermia (OAT) — combined defect.
- Aspermia — no ejaculate (retrograde or anejaculation).
Further workup
- Serum FSH, LH, testosterone, prolactin, TSH.
- Karyotype (Klinefelter 47,XXY in non-obstructive azoospermia), Y-chromosome microdeletion (AZF a/b/c — AZFa worst prognosis).
- Scrotal Doppler for varicocele.
- Transrectal USG for ejaculatory duct obstruction.
- CFTR mutation testing in CBAVD.
Female factor evaluation
Ovulation assessment
- History: regular menses every 21–35 days strongly suggest ovulatory cycles. Oligomenorrhea or amenorrhea points to anovulation.
- Mid-luteal (day-21) serum progesterone >3 ng/mL — confirms ovulation. Best simple test.
- Basal body temperature (BBT) charting — biphasic curve with 0.4–0.8°F rise after ovulation. Cheap, low sensitivity.
- Urinary LH kits detect the LH surge 24–36 hr before ovulation.
- Transvaginal USG follicular tracking — gold standard for documenting follicle growth and rupture.
Ovarian reserve
- AMH (anti-Müllerian hormone) — best marker; cycle-day independent. AMH <1.0 ng/mL suggests diminished reserve.
- Day-3 FSH — >10 mIU/mL indicates reduced reserve; >25 mIU/mL is poor responder.
- Antral follicle count (AFC) — TVS day 2–4. AFC <7 = poor reserve.
Tubal patency
- Hysterosalpingography (HSG) — first-line. Day 6–10 of cycle. Visualises uterine cavity and bilateral tubal patency (free spillage of contrast). Side effects: cramping, infection, allergic reaction.
- Sonohysterography (SHG) — saline infusion sonography; detects polyps and submucous fibroids.
- Laparoscopy with chromopertubation (methylene blue) — gold standard; allows simultaneous treatment (lysis of adhesions, ablation of endometriosis).
- Hysteroscopy — for suspected intrauterine pathology (polyps, septum, Asherman syndrome).
Uterine and cervical factors
- Müllerian anomalies (septate uterus most common, treated by hysteroscopic septoplasty).
- Asherman syndrome — intrauterine adhesions, often post-D&C; managed with hysteroscopic adhesiolysis.
- Cervical stenosis or hostile mucus.
PCOS — the highest-yield infertility cause
Polycystic Ovary Syndrome affects 6–10% of reproductive-age women in India and is the leading cause of anovulatory infertility.
Rotterdam 2003 criteria (2 of 3)
- Oligo- or anovulation.
- Clinical or biochemical hyperandrogenism (hirsutism, acne, elevated testosterone).
- Polycystic ovarian morphology on USG (≥20 follicles per ovary by 2018 update or ovarian volume >10 mL).
Always exclude mimics: thyroid dysfunction, hyperprolactinemia, congenital adrenal hyperplasia (17-OH progesterone), Cushing, androgen-secreting tumour.
Management
| Goal | First-line |
|---|
| Menstrual regulation | Combined OCPs |
| Hirsutism | OCPs + spironolactone after 6 months |
| Anovulatory infertility | Letrozole 2.5–7.5 mg days 2–6 (PPCOS II trial: higher live birth rate than clomiphene) |
| Insulin resistance / obesity | Lifestyle + metformin 1500–2000 mg/day |
| Refractory | Gonadotropins, ovarian drilling, IVF |
OHSS (ovarian hyperstimulation syndrome) is a feared gonadotropin complication in PCOS — high baseline antral follicle count makes them poor responders to standard doses. GnRH antagonist protocols and freeze-all strategies reduce OHSS risk in IVF.
Treatment ladder for infertility
Lifestyle and timed intercourse
- BMI optimisation (target 20–25); even 5–10% weight loss restores ovulation in PCOS.
- Smoking cessation (both partners).
- Folic acid 400–800 mcg/day for at least 3 months pre-conception.
- Timed intercourse around fertile window (day 10–17 in 28-day cycle).
Ovulation induction
- Letrozole 2.5–7.5 mg days 2–6 — first-line for PCOS.
- Clomiphene citrate 50–150 mg days 2–6 — second-line; risk of multiple pregnancy 8–10%.
- Gonadotropins (FSH ± LH) — for clomiphene/letrozole failure or hypogonadotropic hypogonadism.
- GnRH pump for hypothalamic amenorrhea (Kallmann syndrome).
Intrauterine insemination (IUI)
- Indications: mild male factor, cervical factor, unexplained infertility, donor sperm.
- Requirements: at least one patent tube, ≥5 million motile sperm post-wash.
- Success: 10–15% per cycle; offer 3–6 cycles before escalating to IVF.
IVF and ICSI
- IVF: controlled ovarian stimulation → oocyte retrieval (transvaginal USG-guided) → fertilisation in dish → embryo transfer (day 3 cleavage or day 5 blastocyst).
- ICSI (intracytoplasmic sperm injection): indicated for severe male factor (count <5 million, low motility, abnormal morphology), failed prior IVF fertilisation, surgically retrieved sperm (TESE/PESA), pre-implantation genetic testing.
- Live birth rate per cycle: ~30–35% under age 35; falls to <5% over age 42.
Surgical options
- Varicocelectomy (subinguinal microsurgical) — improves semen parameters, especially in clinically palpable varicocele.
- Tubal recanalisation — selected proximal blocks.
- Hysteroscopic resection of polyps, septum, submucous fibroids.
- Laparoscopic ovarian drilling for clomiphene-resistant PCOS.
Indian regulations — ART Act 2021 and Surrogacy Act 2021
ART (Regulation) Act 2021
- Mandatory registration of all ART clinics and ART banks.
- Eligibility: woman aged 21–50; man aged 21–55.
- Sperm donor age: 21–55. Oocyte donor age: 23–35; ever-married woman with at least one healthy living child of her own (≥3 years old). One donor per couple; oocytes from a single donor used for one couple only.
- Mandatory counselling (medical, psychological, ethical) before any procedure.
- Sex selection prohibited (also covered by PC&PNDT Act 1994).
- 25-year record-keeping requirement; audit by National ART Registry.
- Penalties: imprisonment 5–10 years and fine up to Rs 25 lakh for non-compliance.
Surrogacy (Regulation) Act 2021
- Altruistic surrogacy only — commercial surrogacy banned.
- Intending couple must be Indian, married 5+ years, with a medical indication for surrogacy.
- Surrogate must be a close relative aged 25–35, ever-married with at least one own child, only once in lifetime.
- Single woman (widow or divorcee aged 35–45) is also eligible; single men, foreign nationals, and same-sex couples are excluded.
These specifics are testable on NEET PG, INI-CET, and FMGE — the regulations are India-specific and frequently asked.
High-yield NEET PG MCQ traps
- First investigation in infertile couple — semen analysis. Never start with HSG.
- WHO 2021 morphology threshold — 4% strict Kruger (often confused with older 14% Tygerberg).
- Letrozole over clomiphene — current first-line for PCOS infertility (PPCOS II trial).
- Klinefelter karyotype — 47,XXY; small firm testes, gynecomastia, tall stature, high FSH/LH, low testosterone, azoospermia.
- AZFa microdeletion — worst prognosis; sperm rarely retrieved on TESE.
- CBAVD — congenital bilateral absence of vas deferens; >95% have CFTR mutations.
- Day-3 FSH significance — basal FSH >10 = reduced reserve; >25 = poor responder.
- OHSS risk — highest in young, lean PCOS women on gonadotropins; freeze-all strategy + GnRH antagonist reduces risk.
- ART Act age limit — woman 21–50, man 21–55 (often confused with surrogacy ages).
- Surrogate eligibility — close relative, married, age 25–35, only once.
Recent updates and Indian context
- ESHRE 2023 PCOS guidelines: letrozole confirmed first-line; AMH endorsed as diagnostic adjunct in adult women.
- WHO 2021 semen analysis (6th edition): lower reference limits revised — important for NEET PG 2026.
- ASRM 2024: unexplained infertility — IVF after 3 failed IUI cycles or in women over 38 directly.
- Indian ART Act amendments (2023): harmonised reporting framework with Surrogacy Act; mandatory online registration via the National ART Registry.
- PC&PNDT integration — sex selection remains banned; pre-implantation genetic testing for sex is illegal except for sex-linked disorders.
Frequently asked questions
What is the definition of infertility?
Infertility is the inability to conceive after 12 months of regular unprotected intercourse in women under 35, or after 6 months in women 35 years or older. Primary infertility means no prior conception; secondary infertility means inability to conceive after a previous pregnancy. Earlier evaluation is warranted with known risk factors.
What WHO 2021 semen analysis values are considered normal?
WHO 2021 lower reference limits: volume 1.4 mL or more, sperm concentration 16 million per mL or more, total count 39 million per ejaculate, total motility 42% or more, progressive motility 30% or more, normal morphology 4% or more by strict Kruger criteria, vitality 54% or more. Always confirm abnormal results with a repeat sample after 2 to 3 weeks.
What is the day-21 progesterone test?
Mid-luteal serum progesterone (day 21 of a 28-day cycle, or 7 days before expected menses) confirms ovulation when the value exceeds 3 ng/mL — strongly supportive of ovulation; values above 10 ng/mL suggest robust corpus luteum function. It is the simplest and most cost-effective ovulation confirmation test.
What is the first-line ovulation induction agent for PCOS?
Letrozole is now first-line for PCOS-related anovulatory infertility per ESHRE 2023 and ASRM guidelines, having replaced clomiphene. Letrozole shows higher live birth rates (PPCOS II trial) and lower multiple pregnancy risk. Clomiphene is second-line. Metformin is added in obese or insulin-resistant women.
What does the Indian ART Act 2021 require?
The ART (Regulation) Act 2021 mandates registration of all ART clinics and banks, age limits (women 21 to 50, men 21 to 55), mandatory counselling, prohibits sex selection, restricts gamete donation (women donor 23 to 35, oocytes from a single donor used for one couple only), and bans commercial surrogacy. The Surrogacy (Regulation) Act 2021 is a separate law restricting altruistic surrogacy only.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: Pending SME Review
Last reviewed: April 2026
