Infertilitas Wanita

01Pathophysiology

Female infertility results from disruption at any point along the reproductive axis: the hypothalamus, pituitary, ovary, fallopian tube, uterus, or cervix. The key to understanding the pathophysiology is recognizing which level of the axis is affected, because the diagnostic workup and treatment differ accordingly.

Ovulatory dysfunction is the single most commonly tested category. Normal ovulation requires pulsatile GnRH secretion from the hypothalamus, which drives FSH and LH release from the anterior pituitary. FSH stimulates follicular development, and the mid-cycle LH surge triggers ovulation. Any process that disrupts this cascade leads to anovulation or oligo-ovulation. The WHO classifies ovulatory disorders into three groups:

WHO Group I (hypogonadotropic hypogonadism) results from inadequate hypothalamic or pituitary stimulation. Both FSH and estradiol are low. The classic scenario is functional hypothalamic amenorrhea, seen in women with excessive exercise, low body weight, or chronic stress. The hypothalamus reduces GnRH pulsatility, and the entire downstream axis shuts down. These patients present with amenorrhea and estrogen deficiency (no withdrawal bleed after progesterone challenge).

WHO Group II (normogonadotropic, eugonadal anovulation) is the most common group and is overwhelmingly represented by polycystic ovary syndrome (PCOS). In PCOS, excess ovarian androgen production and insulin resistance disrupt follicular maturation. Multiple small follicles accumulate but none reach dominance, resulting in chronic anovulation. FSH is normal to low, LH is often disproportionately elevated (LH:FSH ratio greater than 2:1), and androgens are elevated. These patients typically have irregular menses, hirsutism, and acne.

WHO Group III (hypergonadotropic hypogonadism) indicates ovarian failure. The ovaries no longer respond to gonadotropin stimulation, so FSH rises markedly via loss of negative feedback. This is seen in premature ovarian insufficiency (previously called premature ovarian failure) in women under 40. Causes include Turner syndrome mosaicism (45,X), autoimmune oophoritis, prior chemotherapy or radiation, and FMR1 premutations (fragile X carrier status). Estradiol is low and FSH is elevated above 40 mIU/mL on two occasions at least one month apart.

Tubal and peritoneal factors account for approximately 30% of cases. The most common cause is pelvic inflammatory disease (PID), particularly from Chlamydia trachomatis, which causes tubal scarring and adhesion formation. Each episode of PID roughly doubles the risk of tubal infertility. Endometriosis can also cause peritoneal adhesions and distort tubal anatomy. The fallopian tube is not merely a conduit; it provides the microenvironment for fertilization and early embryo transport. Damage to the tubal epithelium or obstruction prevents sperm-oocyte interaction.

Uterine factors are less common but important. Submucosal leiomyomas distort the endometrial cavity and impair implantation. Asherman syndrome (intrauterine adhesions), typically following aggressive curettage, destroys the endometrium and causes amenorrhea with cyclic pelvic pain. Mullerian anomalies such as a uterine septum increase the risk of recurrent pregnancy loss rather than primary infertility, but a septate uterus is the most common anomaly associated with adverse reproductive outcomes.

Cervical factors are rarely the sole cause but can contribute. Inadequate or hostile cervical mucus, prior cervical procedures (cone biopsy, LEEP), or cervical stenosis can impair sperm transit.

A point that exam questions emphasize: male factor contributes to approximately 40% of infertile couples, so a semen analysis must be obtained early in the evaluation, not after an exhaustive female workup.

02Classification and Clinical Manifestation

WHO Classification of Ovulatory Disorders

Classification by Anatomic and Functional Etiology

Endometriosis-Related Infertility (Revised ASRM Staging)

03Diagnostic Workup

The evaluation of an infertile couple should begin simultaneously in both partners. Exam questions commonly test whether you obtain a semen analysis early rather than putting the male partner through testing only after the female workup is complete. A semen analysis is inexpensive, noninvasive, and rules out a contributing factor in nearly half of cases. This is a frequently tested "next best step."

Confirming ovulation is the first priority in the female workup. The best initial test is a mid-luteal serum progesterone, drawn approximately 7 days before expected menses (day 21 in a 28-day cycle, day 28 in a 35-day cycle). A level greater than 3 ng/mL confirms that ovulation occurred. This is the single most tested lab value in infertility vignettes. An alternative is serial transvaginal ultrasound showing follicular development and collapse, but this is more resource-intensive and typically reserved for monitored cycles. Urinary LH kits (ovulation predictor kits) detect the LH surge but do not confirm that ovulation actually followed, making them less reliable for clinical confirmation.

Ovarian reserve testing determines how the ovaries will respond to stimulation and helps guide prognosis. The two most commonly tested markers are cycle day 3 FSH (with concurrent estradiol) and AMH. An FSH above 10 mIU/mL on day 3 indicates diminished reserve. However, a normal FSH does not guarantee adequate reserve if estradiol is simultaneously elevated above 80 pg/mL, because high estradiol can suppress FSH through negative feedback, masking true ovarian depletion. This is a classic exam trap. AMH is increasingly favored because it can be drawn on any cycle day and correlates well with antral follicle count. Antral follicle count on ultrasound (counting follicles 2 to 10 mm on days 2 to 4) is another reliable reserve marker.

Hormonal screening with TSH and prolactin should be performed at baseline. Hypothyroidism causes anovulation through elevated TRH, which stimulates prolactin release. Hyperprolactinemia from any cause (prolactinoma, medications, hypothyroidism) suppresses GnRH pulsatility and causes anovulation, often with galactorrhea and amenorrhea. If prolactin is elevated, obtain a pituitary MRI to rule out a prolactinoma.

Tubal patency assessment is performed via hysterosalpingography (HSG), which is the best initial test for tubal evaluation. HSG involves injecting radiopaque contrast through the cervix and obtaining fluoroscopic images. Normal findings show contrast filling the uterine cavity and bilateral free spillage from the fimbriated ends. HSG also has a mild therapeutic benefit: the flushing of oil-based contrast through the tubes modestly increases pregnancy rates in the 6 months following the procedure. Limitations of HSG include a false-positive rate for proximal tubal occlusion (tubal spasm can mimic obstruction) and inability to diagnose peritoneal disease. If HSG is abnormal or if there is strong clinical suspicion for endometriosis or adhesions, laparoscopy with chromopertubation is the gold standard for definitive tubal and peritoneal assessment.

Uterine cavity evaluation is best performed with sonohysterography (saline infusion sonography) or hysteroscopy. HSG provides some uterine cavity information but is inferior to these modalities for detecting submucosal fibroids, polyps, and adhesions. Hysteroscopy is the gold standard because it allows direct visualization and simultaneous treatment.

The workup sequence a test-writer expects you to follow:

1. History and physical in both partners

2. Semen analysis (male factor)

3. Confirm ovulation (day 21 progesterone)

4. Ovarian reserve (day 3 FSH/estradiol, AMH)

5. Tubal patency (HSG)

6. Uterine cavity evaluation if indicated

7. Laparoscopy only when noninvasive testing is inconclusive and clinical suspicion for peritoneal disease is high

04Management and Treatment

Ovulation induction is the cornerstone of treating anovulatory infertility. For PCOS (WHO Group II), letrozole has replaced clomiphene as the preferred first-line agent based on the landmark NICHD trial, which demonstrated higher live birth rates and lower multiple pregnancy rates with letrozole compared to clomiphene. Letrozole is an aromatase inhibitor that reduces peripheral estrogen conversion, thereby releasing the hypothalamus from negative feedback and increasing endogenous FSH secretion. It is dosed at 2.5 mg daily starting on cycle day 3 through day 7, with dose escalation up to 7.5 mg if no ovulatory response. Clomiphene citrate, a selective estrogen receptor modulator, remains an acceptable alternative. It is dosed at 50 mg daily on cycle days 5 to 9, increasing by 50 mg increments per cycle up to a maximum of 150 mg. Clomiphene works by blocking estrogen receptors at the hypothalamus, which reduces negative feedback and increases FSH release. A critical point: clomiphene has antiestrogenic effects on the endometrium and cervical mucus, which is why it can paradoxically decrease implantation rates despite successful ovulation. This is one reason letrozole is now favored.

For patients with PCOS and insulin resistance, metformin (1500 to 2000 mg daily) can be added as an adjunct to improve ovulatory response, though it is not effective as monotherapy for fertility.

If oral agents fail after 3 to 6 cycles, the next step is gonadotropin therapy with injectable FSH (e.g., recombinant FSH at 75 to 150 IU daily with dose titration based on ultrasound follicular monitoring). Gonadotropin therapy carries a higher risk of ovarian hyperstimulation syndrome (OHSS) and multiple gestations, requiring close monitoring with serial ultrasound and estradiol levels. OHSS is characterized by ovarian enlargement, ascites, pleural effusion, hemoconcentration, and in severe cases, thromboembolic events.

For WHO Group I (hypothalamic amenorrhea), addressing the underlying cause is paramount: weight restoration in underweight patients, reducing excessive exercise, and managing stress. Pharmacologically, pulsatile GnRH therapy is the physiologically ideal treatment because it restores the normal hypothalamic signal. When pulsatile GnRH is unavailable, exogenous gonadotropins (combined FSH and LH) are used. Clomiphene does not work in these patients because it requires an intact hypothalamic-pituitary-ovarian axis with baseline estrogen activity, which is absent in Group I.

For WHO Group III (premature ovarian insufficiency), the follicle pool is depleted or nonfunctional. No amount of gonadotropin stimulation will produce viable oocytes. The only realistic path to pregnancy is donor oocyte IVF. These patients should also receive hormone replacement therapy (estrogen plus progesterone) for long-term bone, cardiovascular, and vasomotor symptom management.

For hyperprolactinemia, cabergoline is the treatment of choice. It is a dopamine agonist that directly suppresses prolactin secretion from the anterior pituitary. Dosing begins at 0.25 mg twice weekly and is titrated based on prolactin levels. Cabergoline is preferred over bromocriptine because of superior efficacy, longer half-life, and fewer gastrointestinal side effects. Prolactin normalization restores GnRH pulsatility and ovulatory function in most patients. For macroadenomas (greater than 10 mm), MRI monitoring is needed, and surgical resection (transsphenoidal approach) is reserved for tumors unresponsive to medical therapy or causing compressive symptoms.

For tubal factor infertility, IVF is the treatment of choice because it bypasses the tubes entirely. A critical exam point: if a hydrosalpinx is present, it must be removed (salpingectomy) or proximally occluded before IVF. Hydrosalpinx fluid is embryotoxic and leaks into the uterine cavity, reducing IVF implantation rates by approximately 50%. This "salpingectomy before IVF" principle is heavily tested.

For endometriosis-related infertility, laparoscopic ablation or excision of endometriotic implants improves natural fecundity in mild to moderate disease. After surgery, patients proceed with ovulation induction and timed intercourse or IUI. For severe disease (stage III to IV), IVF is typically necessary. An important point: medical suppression of endometriosis (with GnRH agonists, progestins, or combined oral contraceptives) does not improve fertility and actually delays conception by preventing ovulation during treatment. This is a frequent distractor on exams.

For uterine factors, hysteroscopic surgery is both diagnostic and therapeutic. Submucosal fibroids, endometrial polyps, uterine septa, and intrauterine adhesions (Asherman syndrome) are all amenable to hysteroscopic resection. For Asherman syndrome, lysis of adhesions is followed by placement of an intrauterine balloon or IUD and estrogen supplementation to promote endometrial regrowth.

For unexplained infertility, the empiric approach is superovulation plus IUI for 3 to 4 cycles, using either clomiphene or letrozole to produce 2 to 3 mature follicles while IUI places washed sperm directly into the uterine cavity. If this fails, IVF is the next step.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on infertility questions is by failing to order a semen analysis early. When presented with a couple unable to conceive, many test-takers default to an extensive female-only workup. The exam consistently rewards the answer that includes male evaluation in the initial assessment, because male factor is present in nearly 40% of cases and a semen analysis is low-cost and noninvasive.

A second major trap involves ovarian reserve interpretation. Students correctly identify an elevated day 3 FSH as a marker of diminished reserve but fail to check the concurrent estradiol. If estradiol is elevated above 80 pg/mL on the same day 3 draw, the "normal" FSH is being artificially suppressed and should not be trusted. The exam tests whether you recognize this false reassurance.

Another frequently tested concept is the distinction between WHO Group I and Group III anovulation based on the FSH level. Both present with amenorrhea and low estrogen, but the FSH tells you whether the problem is central (low FSH, the brain is not sending the signal) or peripheral (high FSH, the ovary is not responding). This single lab value determines the entire treatment strategy: gonadotropins or pulsatile GnRH for Group I versus donor oocyte IVF for Group III. Students who memorize treatments without understanding this physiologic framework will select the wrong therapy.

Clomiphene in hypothalamic amenorrhea is a deliberate distractor. Because clomiphene is a "first-line ovulation induction agent," students reflexively choose it for any anovulatory patient. However, clomiphene requires intact hypothalamic-pituitary signaling and baseline estrogen activity to work. In WHO Group I, both are absent, and clomiphene will fail.

For tubal factor, the trap is proceeding directly to IVF when a hydrosalpinx is present. The correct next step is salpingectomy first, then IVF. Hydrosalpinx fluid is embryotoxic and dramatically reduces implantation. Skipping this step is a commonly tested error.

Finally, students often incorrectly select medical suppression (GnRH agonists, oral contraceptives) as treatment for endometriosis-related infertility. While these medications reduce endometriotic implants and relieve pain, they suppress ovulation and therefore directly prevent conception during treatment. They have no role in the management of infertility due to endometriosis. The correct approach is surgical ablation followed by ovulation induction or IVF.

The core competencies being tested in infertility questions are: systematic evaluation of both partners, correct interpretation of hormonal levels to localize the defect, appropriate test sequencing (noninvasive before invasive), and matching the treatment to the underlying etiology rather than applying a one-size-fits-all approach.