ABOG Reproductive Endocrinology and Infertility key terms

A hypothalamic network of KNDy neurons that releases gonadotropin-releasing hormone in discrete pulses, driving pulsatile pituitary LH and FSH secretion; pulse frequency and amplitude differentially favor LH or FSH release.

A peptide produced by hypothalamic neurons that stimulates GnRH secretion and is required for pubertal activation of the reproductive axis; its signaling is modulated by steroid feedback and metabolic cues.

A tachykinin co-expressed in KNDy neurons that acts as an autocrine/paracrine regulator of GnRH pulse frequency; its antagonist (NK3 receptor blocker) suppresses LH and is under study for vasomotor symptoms.

Tuberoinfundibular dopamine tonically inhibits pituitary lactotroph prolactin release; interruption of dopamine delivery (stalk lesion, drug blockade) causes hyperprolactinemia, which suppresses GnRH and causes hypogonadism.

Failure of gonadal function due to deficient hypothalamic or pituitary gonadotropin secretion, producing low estradiol, low or normal gonadotropins, and absent or disordered ovulation; causes include functional, congenital, and structural disorders.

Reversible suppression of GnRH pulsatility from energy deficit, stress, or excessive exercise, causing amenorrhea with low gonadotropins and hypoestrogenism after other causes are excluded.

Congenital hypogonadotropic hypogonadism with anosmia or hyposmia, caused by failed migration of GnRH and olfactory neurons; inheritance may be X-linked, autosomal dominant, or recessive.

A common endocrine disorder diagnosed by at least two of ovulatory dysfunction, clinical or biochemical hyperandrogenism, and polycystic ovarian morphology, after excluding mimics; it is associated with insulin resistance and cardiometabolic risk.

Excess androgen production or action causing hirsutism, acne, or virilization, with elevated serum androgens; sources include ovarian, adrenal, and peripheral conversion, and rapid virilization warrants tumor evaluation.

Persistent failure to release an oocyte, leading to irregular or absent menses and unopposed estrogen exposure; causes include PCOS, thyroid disease, hyperprolactinemia, and hypothalamic dysfunction.

Pharmacologic stimulation of follicular development and oocyte release in anovulatory women, using agents such as letrozole, clomiphene, or gonadotropins with monitoring for multifollicular development.

Gonadotropin-driven recruitment of multiple follicles for assisted reproduction, typically with pituitary suppression to prevent premature LH surge, followed by trigger and timed oocyte retrieval.

An iatrogenic complication of ovarian stimulation marked by ovarian enlargement, capillary leak, hemoconcentration, ascites, and risk of thrombosis; risk rises with high follicle number, high estradiol, and pregnancy.

A stimulation regimen using a GnRH receptor antagonist to immediately block pituitary gonadotropin release, shortening treatment and lowering OHSS risk when combined with a GnRH agonist trigger.

A single agonist dose after stimulation that causes a short gonadotropin surge to mature oocytes while reducing OHSS risk compared with hCG, at the cost of a shorter luteal phase requiring support.

Elective cryopreservation of all embryos with transfer in a later unstimulated or hormonally prepared cycle, avoiding fresh transfer in a supraphysiologic hormonal environment and reducing OHSS risk.

Microinjection of a single sperm directly into a mature oocyte, used for severe male factor, prior fertilization failure, or preimplantation genetic testing to avoid contaminating DNA.

Absence of sperm in the ejaculate, classified as obstructive or nonobstructive; evaluation includes volume, hormones, and physical exam, and surgical sperm retrieval may be possible in some cases.

Infertility attributable to abnormal semen parameters or male reproductive tract pathology, present in roughly half of infertile couples either alone or with female factors; evaluation includes semen analysis and targeted endocrine or genetic testing.

Laboratory assessment of ejaculate volume, concentration, motility, and morphology against reference limits; abnormal results require repeat testing because of biologic variability.

Dilatation of the pampiniform plexus, usually left-sided, associated with impaired spermatogenesis and potentially correctable by ligation in selected men with abnormal semen parameters.

An operating-microscope technique to identify and harvest seminiferous tubules likely to contain sperm in men with nonobstructive azoospermia, for use with intracytoplasmic sperm injection.

Two or more consecutive clinical pregnancy losses, prompting evaluation for uterine anomalies, antiphospholipid antibodies, parental chromosomal rearrangements, and endocrine or thrombotic contributors.

An acquired autoimmune thrombophilia defined by vascular thrombosis or pregnancy morbidity plus persistent antiphospholipid antibodies; treatment in pregnancy typically combines low-dose aspirin with heparin.

A structural chromosomal rearrangement with exchanged segments and no net loss of genetic material; carriers are usually healthy but risk unbalanced gametes, causing recurrent loss or offspring with anomalies.

Analysis of embryos before transfer to detect aneuploidy, monogenic disease, or structural rearrangements, using trophectoderm biopsy and technologies such as comprehensive chromosome screening or targeted assays.

Presence of two or more cell lines with different chromosomal complements in an embryo or individual; in embryo testing, low-level mosaicism complicates interpretation and counseling regarding transfer.

Loss of ovarian function before age 40 with amenorrhea, elevated FSH, and low estradiol; causes include genetic, autoimmune, and iatrogenic factors, and hormone therapy is needed until natural menopause age.

Systemic estrogen, with progestogen when a uterus is present, used for vasomotor symptoms and genitourinary syndrome; risk-benefit depends on age, time since menopause, dose, route, and duration.

Hot flushes and night sweats arising from thermoregulatory instability during estrogen withdrawal; they are the most common menopause symptom and respond to estrogen therapy and nonhormonal alternatives.

Vaginal dryness, irritation, dyspareunia, and urinary symptoms resulting from estrogen deficiency; local vaginal estrogen or nonhormonal moisturizers are first-line options.

A müllerian anomaly with a midline uterine septum dividing the cavity, associated with recurrent pregnancy loss and amenable to hysteroscopic resection in selected patients.

A congenital malformation of the uterus, cervix, or vagina resulting from abnormal fusion or resorption of the paramesonephric ducts, ranging from septate and bicornuate uteri to agenesis.

Absence of menarche by age 15 with normal growth and secondary sexual development, or by age 13 without breast development; evaluation addresses outflow obstruction, gonadal failure, and central causes.

Complete or partial loss of an X chromosome causing short stature, gonadal dysgenesis, and primary ovarian insufficiency; fertility preservation counseling and cardiac and endocrine surveillance are essential.

Interventions before gonadotoxic therapy or with age-related decline to protect reproductive potential, including oocyte, embryo, and ovarian tissue cryopreservation and sperm banking.

The multidisciplinary field coordinating timely fertility preservation and reproductive counseling for patients facing cancer or gonadotoxic treatment, integrating oncology and reproductive care.

Vitrification of mature oocytes for later thaw and fertilization, used for elective age-related preservation or before gonadotoxic therapy; outcomes depend strongly on age at retrieval and oocyte yield.

Methods used after unprotected intercourse to prevent pregnancy, including copper IUD, levonorgestrel, and ulipristal, with efficacy influenced by timing and body weight.

A long-acting reversible contraceptive placed in the uterus that thickens cervical mucus and thins endometrium, with additional noncontraceptive benefits such as reduced menstrual bleeding.

Shared decision-making that matches method choice to a patient's medical history, preferences, and goals, including discussion of effectiveness, side effects, and return to fertility.

Surgical removal of an ovarian cyst or endometrioma, preferably by minimally invasive technique with ovarian preservation; excessive coagulation can reduce ovarian reserve.

An ovarian cyst lined by endometriotic tissue, often associated with pelvic pain and infertility; management balances symptom control and fertility goals against surgical risk to ovarian reserve.

The quantity and quality of remaining oocytes, estimated by age, antral follicle count, and anti-müllerian hormone; it predicts response to stimulation but not spontaneous fertility with certainty.

A glycoprotein secreted by granulosa cells of small antral follicles that reflects ovarian reserve and declines with age; it is used to predict ovarian response and assess premature ovarian insufficiency.

A process helping patients understand inheritance, recurrence risk, and testing options for reproductive conditions, supporting informed decisions about screening, prenatal diagnosis, and embryo testing.

A patient's voluntary agreement after receiving and understanding information about diagnosis, options, risks, benefits, and alternatives, documented as part of ethical reproductive care.

A collaborative process in which clinician expertise and patient values jointly guide care choices, particularly when evidence is uncertain or options carry trade-offs.

A core competency in which clinicians critically appraise their own outcomes and the literature, use quality data, and adjust practice to improve patient care.