Info
🌱 來自: Huppert’s Notes
Females🚧 施工中
Females
Menstrual Cycle
• Follicular phase (day 0–13): From the onset of menses to the LH surge. The follicle develops during this phase. Estradiol inhibits FSH and LH during this phase and promotes endometrial healing. Rising estradiol causes menstruation to end.
• Ovulation (day 14): The dominant follicle secretes estradiol. Estradiol increases above a level such that it now positively feeds back to increase LH/FSH, and the resultant LH surge causes ovulation.
• Luteal phase (day 15–28): The corpus luteum produces estrogen. If the corpus luteum is not fertilized, it involutes and progesterone production declines. If it is fertilized, the zygote secretes bHCG, which sustains the corpus luteum.
FIGURE 5.6: Concentrations of hormones throughout the menstrual cycle. The menstrual cycle is regulated by the complex interactions of four hormones: estrogen, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). There are three phases, as described in the text.
Amenorrhea
Primary amenorrhea
• Definition: Absent menses at age 15 yr
• Etiologies:
- Genetic (50%): Turner’s syndrome (XO karyotype) – patients may have a webbed neck, coarctation of the aorta. Diagnosis: High FSH, check karyotype.
- Hormonal (35%): Low sex hormones due to excessive exercise, anorexia, craniopharyngioma. Diagnosis: Low FSH, consider brain MRI.
- Anatomic/structural (15%): Müllerian agenesis, transverse vaginal septum, imperforate hymen. Diagnosis: Transvaginal ultrasound.
Secondary amenorrhea
• Definition: Absent menses for >3 months in women with previously regular menstrual cycles or >6 months if irregular menstrual cycles
• Etiologies:
- Pregnancy (always rule out first!)
- Ovarian: Polycystic ovarian syndrome (PCOS), ovarian failure (↑FSH)
- Hypothalamic: Stress, exercise, systemic illness, and weight loss can result in functional hypothalamic amenorrhea (disruptions in pulsatile release of hypothalamic GnRH)
- Pituitary: Prolactinoma (↑prolactin), empty sella syndrome
- Endocrine: Hypo/hyperthyroidism, diabetes, obesity (normal FSH/LH but anovulation because progesterone dysregulation)
- Uterine: Asherman’s syndrome post dilation and curettage (D&C)
• Diagnosis: Urine pregnancy test, FSH, LH, prolactin, estradiol, TSH. Abnormal findings will guide management. If normal: Progesterone challenge can further assess estrogen status and functional anatomy. If progesterone challenge provokes menses, then the patient has a normal estrogen state; consider hyperandrogenism.
Hyperandrogenism syndromes
Polycystic Ovarian Syndrome (PCOS)
• Symptoms: Weight gain, male pattern baldness, acne, oligomenorrhea. Risk endometrial cancer due to unopposed estrogen.
• Criteria: Need two of the following: 1) Oligomenorrhea/anovulation; 2) Clinical/biochemical evidence of hyperandrogenism (hirsutism, acne); 3) Polycystic ovaries on pelvic ultrasound
• Diagnosis:
- Diagnosis of exclusion (rule out thyroid dysfunction, congenital adrenal hyperplasia, hyperprolactinoma)
- Labs/imaging not required for diagnosis unless needed to satisfy diagnostic criteria and/or to rule out other diagnoses (e.g., rapid-onset hirsutism with concern for malignancy)
- If PCOS is diagnosed, also screen patient for diabetes, HLD, HTN, and OSA
• Treatment:
- Oral contraceptive pills
- Weight loss
- Metformin if diabetes or impaired oral glucose tolerance testing
Other causes of hirsutism/virilization
• Congenital adrenal hyperplasia (CAH, e.g., 21-hydroxylase deficiency): Accumulation of 17-OH-progesterone → DHEA
• Adrenal neoplasm: Rapid hair growth, amenorrhea, virilization. If DHEA >7.0 mg/dL, get CT abdomen/pelvis protocoled to evaluate the adrenal glands.
• Ovarian neoplasms: Sertoli-Leydig cell tumors secrete testosterone. Rapid-onset acne, hirsutism, amenorrhea. If testosterone >150 ng/dL, obtain pelvic ultrasound.
Infertility
• Definition: Failure to conceive after 12 months of unprotected sex (~2×/wk) in women <35 yr and after 6 months in women ≥35 yr. For most women in 20s to low 30s one menstrual cycle = approximately 25% chance of getting pregnant.
• Etiologies:
- Issues with ovulation: PCOS, anovulation. Diagnosis: 1) Day 21 progesterone, 2) FSH: Check ovulatory reserve (high FSH suggests less reserve), 3) Anti-Müllerian hormone, 4) Pelvic ultrasound (check if follicles present).
- Blocked transport of the egg getting from the ovaries to the uterus: Pelvic inflammatory disease (PID), tuberculosis (particularly in endemic areas), fibroids, adhesions. Diagnosis: Hysterosalpingogram.
- Idiopathic: Endometriosis
- Semen analysis: Volume, motility, morphology. Diagnosis: Semen analysis. Ddx azospermia (no sperm): Cystic fibrosis, XXY Klinefelter’s.
• Diagnosis: Both partners should be evaluated concurrently for causes of infertility. For females, evaluate ovulatory function (midluteal progesterone) and for anatomic abnormalities (hysterosalpingogram). For males, perform semen analysis.
• Treatment:
- Clomiphene (selective estrogen receptor modulator [SERM]—inhibits estrogen binding at hypothalamus/pituitary so release FSH/LH): Increases ovulation 2–3 fold
- If the patient has PCOS, metformin can improve fertility
- Assisted reproductive technologies, such as intrauterine insemination, in vitro fertilization (IVF):
• Use GnRH agonist leuprolide to shut down LH
• Give FSH to target the release of 10 eggs; evaluate with pelvic ultrasound and estradiol levels
• Give LH to cause ovulation
• Harvest eggs approximately 36 hours later. Can freeze as eggs (without insemination) or embryos (inseminate prior to freezing).