OB/GYN III Flashcards
How is a molar pregnancy categorized
abnormal proliferation of the placental trophoblastic cells Abnormal cells distend the uterus and secrete hCG, mimicking a normal pregnancy. There are 2 types complete (classic) and partial (incomplete)
What defines a complete mole
Empty ovum fertilized by sperm.
46XX by one sperm occurs 90% of the time
46XX or 46 XY by two sperm occurs 10%
What is the most common clinical presentation of a molar pregnancy
Abnormal uterine bleeding (most common)
Uterine size greater than expected for GA
lack of fetal heart tones
hCG greater than 100,000 and uterine cavity filled with small vessicles
What defines an incomplete mole
a normal ovum is fertilized by two sperm. The resulting karyotype is 69 XXX, XXY, or XYY
A fetus may or may not be present, but will not viable if present
What are the most common clinical presentation of an incomplete molar pregnancy
Abnormal heavy bleeding
hCG is not as elevated as it is with a complete mole
Many spontaneous abortions are the result of a partial mole
How long should a patient wait for reattempting pregnancy following a molar pregnancy
at least 1 year
Gestational Trophoblastic Tumors may become metastatic to what locations
Lung (80%)
Vagina (30%)
Liver (10%)
Brain (10%)
How is a GTT diagnosed
After evacuation of a molar pregnancy
- increase in hCG
- the value of hCG reaches a plateau for 3 weeks
- metastatic disease is identified
What is used to treat non metastatic GTT
Single agent chemotherapy
- Methotrexate
- Actinomycin D
What drug is given with methotrexate to preserve normal cells
leucovorin
What is the mechanism of methotrexate
Anitmetabolite inhibits purine synthesis by blocking the dihydrofolate reductase enzyme required to process folic acid. Results in arrested synthesis of DNA, RNA and proteins
What is the mechanism of actinomycin D
Antibiotic that intercalates DNA strands
How should you monitor a patient with GTT
hCG titers should be taken weekly until normal fro 3 months, then monthly for 6 months
Contraception is preferred for 1 year
What carries a good prognosis with metastatic GTT
Rules of 4
- duration less than 4 months
- less than 40,000 hCG pretreatment
- No foreign metastasis to brain or liver
- no previous chemotherapy
What is the treatment for poor prognosis metastatic GTT
EMA-CO
Etoposide Methotrexate Actinomycin D Cyclophosphamide Oncovin (vincristine)
How long should treatment last for poor prognosis metastatic GTT
Three additional chemo sessions after a negative hCG titer
What are the phases of the menstrual cycle
Follicular
Secretory
What is polymenorrhea
menstrual cycles that last less than 21 days in duration
What is oligomenorrhea
menstrual cycles that last more than 35 days in duration
When are menstrual cycles most irregular
2 years following menarche
3 years preceding menopause
During both times anovulation is common
What is the follicular or proliferative phase
lasts from the first day of menses until ovulation, during which time follicles within the oveary grow in response to FSH and in the uterus enometrial glands proliferate under the influence of estrogen, primarily estradiol produced by the follicle
Characterized by:
Variable length (average of 14 days)
development of ovarian follicles in response to FSH
Secretion of estrogen from the ovary
Proliferation of the endometrium in response to estrogen
Low basal body temperature
What causes ovulation to occur
response to the LH surge
Characterized by:
release of the oocytes from the follicle in response to FSH induction of collagenases
Resumption of meiosis, with oocytes progressing from prophase I to metaphase II
Formation of the corpus luteum with in the follicle
What is the luteal or secretory phase
Begins with ovulation and last until menses
The corpus luteum, stimulated by LH, produces progesterone, which causes secretory changes in the endometrium necessary fro preparing the endometrium for implantation.
What characterizes the luteal phase
Fairly constant duration of 12-16 days
elevated basal temperature in response progesterone production
sustaining of the corpus lute in the ovary
Where is GnRH produced and what is the frequency of release
Produced by hypothalamic neurons from the arcuate nucleus and transported to the portal plexus to the anterior pituitary.
Released in a pulsatile manner:
Follicular phase has one pulse every 60-90 minutes
Luteal phase has one pulse ever 2-3 hours
Amplitude and frequency is modulated by feedback of estrogen and progesterone
What is the role of FSH
production of estrogen and growth of the follicle. FSH receptors exist primarily on the ovarian granulosa cell membrane
What is the role of LH
responsible for the initiation of the luteal phase (ovulation) and maintenance of the luteal phase of the menstrual cycle
LH receptors exist primarily on ovarian theca cells at all stages of the cycle and on granulosa cells after the follicle matures under the influence of FSH and estradiol
What is the 2 cell hypothesis of estrogen production
- LH acts on the theca cells to stimulate the conversion of cholesterol to androgens
- Androgens are transported from the theca cells to the granulosa cells
- Under the influence of FSH, androgens are aromatized to form estrogens by the enzyme aromatase in the granulosa cells
What are the key steps in the process of oogenesis
- primordial follicle
- Primary follicle
- Preantral follicle
- Antral follicle
- Preovulatory follicle
- Ovulation
- Early corpus luteum
- Mature corpus luteum
- Corpus Albicans
What is a primordial follicle
contains an oocyte surrounded by a single layer of granulosa cells. Each oocyte is arrested in Prophase I
A woman is born with a finite number of follicles that peaks at 20 weeks gestation. The decline is independent of the menstrual cycle and ovulation
What are the estrogen effects on the preantral follicle
- stimulates preantral follicle growth
- with FSH, increases FSH receptor content of the follicle
- in the presence of FSH, stimulate mitosis of granulosa cells
What are the effects of the follicular increase of estradiol
Negative feedback on FSH
positive feed back on LH
Where is inhibin secreted from
granulosa cells in response to FSH
What are the two types of inhibin
Inhibin A: under the influence of LH suppresses FSH during the luteal phase of the cycle.
Inhibin B: directly suppresses pituitary FSH secretion in the follicular phase of the cycle
What is activin
Augments secretion of FSH and increases pituitary response to GnRH by enhancing GnRH receptor formation on the pituitary
When do estrogens peak
24-36 hours before ovulation
What is the effect of LH on the follicle
initiates luetinization and progesterone production
What effect does a preovulatory rise in progesterone have
causes a midcycle FSH surge by enhancing pituitary response to GnRH and facilitating the positive feedback action of estrogen
When does ovulation occur
10-12 hours after peak of LH
24-36 hours after peak of Estradiol
When can an oocyte become fertilized
only after it has reached metaphase II
What does the LH surge stimulate
Resumption of meiosis in the oocyte
Luteinization of the granulosa cell
Synthesis of progesterone and prostaglandin
When are peak levels of progesterone obtained
7-8 days after ovulation
What happens in the absence of pregnancy to the corpus luteum
will undergo apoptosis and cease to produce progesterone by 12-14 days after ovulation
What effect does the decrease in estrogen and progesterone have on the endometrium
leads to coiling and constriction of the spiral arteries in the endometrium
What causes menstrual cramps
the result of uterine contraction which are stimulated by prostaglandins. Therefore the cramps can be controlled with prostaglandin synthetase inhibitors (NSAIDs)
What is amenorrhea
absence of menses for 6 months or longer
What is primary amenorrhea
Absence of menses by 14 years of age ingirls without appropriate development of secondary sexual characteristics or by 16 years of age regardless of secondary sex characteristics
What are the categories of amenorrhea
Hypergonadotropic: elevated gonadotropins (typically FSH more than 20 IU/L; LH more than 40 IU/L)
Hypogonadotropic: low levels of gonadotropins (FSH and LH less than 5 IU)
Eugonadotropic: normal gonadotropin levels (FISH and LH of 5-20 IU/L)
What are the etiologies of hypergonadotropic amenorrhea
- turner syndrome
- Premature ovarian failure
- Gonadal dysgenesis
- Gonadal agenesis
- Resistant ovary syndrome
- Galactosemia
- Enzyme deficiency
What are the phenotypic characteristics of turner syndrome
Short stature
webbed neck
shield chest
increased carrying angle at the elbow
What are the etiologies of hypogonadotropic amenorrhea
- anorexia
- Female athlete triad
- Kallman syndrome
- Postpill amenorrhea
- Medication or drugs
- Pituitary disease
- Stress
- Delayed puberty
What is the female athlete triad
Syndrome of disordered eating, amenorrhea, and osteopenia or osteoporosis
What percent of body fat is generally needed to initiate menarche and maintain regularity
17% to initiate
22% to maintain
What is kallman syndrome
Deficient secretion of GnRH associated with anosmia or hyposmia.
Involves the failure of olfactory axonal and GnRH neuronal migration from the olfactory placode in the nose
How does stress lead to amenorrhea
stress leads to an increased output of corticotropin releasing hormone, which subsequently results indecreased GnRH pulsatile secretion and thus decreased secretion of FSH and LH
What are the etiologies of Eugonadotropic amenorrhea
- Disorders of Androgen excess (PCOS)
- Disorders of the outflow tract or uterus
a. Mullerian agenesis
b. Mullerian anomalies
c. androgen insensitivity syndrome (AIS)
d. Asherman Syndrome
What is the triad assocated with PCOS
- Menstrual irregularity signifying oligo or anovulations
- Appearance of multiple small ovarian cysts on ultrasound “string of pearls”
- Clinical or laboratory evidence of hyperandrogenism
loss of 5-10% body weight may help patients reestablish ovulatory cycles.
When and how may an imperforate hymen present
generally not until 6-12 months after menarche. The vagina maybe distended with more than 1 Liter of old blood
What is the problem with Androgen insensitivity syndrome
The defect is in the androgen receptor and can not respond to the androgen. The individual is phenotypically female and is usually raised female
Testosterone levels will be in the male range, but they will not have any pubic or axillary hair. Normal breast development because the testosterone is converted to estrogen
Gonadectomy is required to prevent gonadoblastoma
What should be suspected if a female patient presents with bilateral inguinal hernia
AIS
What is asherman syndrome
Intrauterine scarring usually a result of viorous curettage during a hypoestrogenic state or in the presence of an intrauterine infection.
Adhesions can develop
What is the goal of hormone replacement for the treatment in patients with hypergonadotropic amenorrhea
prevent bone loss, vasomotor symptoms, urogenital atrophy, and cardiovascular disease due to lack of estrogen
When is it safe to consider an estrogen only treatment
in women without a uterus
Progesterone is needed as it is protective of the uterus
What is the mechanism behind using OCP for the treatment of PCOS
Progestin component suppresses endogenously elevate LH levels, thereby decreasing androgen overproduction
Estrogen component of the pill increases the sex hormone binding globulin levels thereby decreasing the amounts of free estrogens and androgens
What is the rotterdam criteria
It is the criteria established in 2003 that is used to diagnose PCOS. It requires 2 of the following 3:
a. Menstrual irregularities
b. Hyperandrogenism
c. Polycystic ovaries
What are the results of irregular ovulations
lack of adequate progesterone and experience chronic estrogen exposure to the endometrium. Increases risk for endometrial hyperplasia and endometrial cancer
What is the Ferriman-Gallwey score
It is a score used for diagnosing hirsutism.
Greater than 8 is an abnormal score
If a patient experience an rapid onset of hirsutism, what is the most likely etiology
Drug induced or Androgen secreting tumor
Suspect a tumor with levels of testosterone greater than 200 ng/dL
PCOS will likely have a more gradual onset of hirsutism
What defines polycystic ovaries by ultrasound criteria
12 or more antral follicles between 2 and 9 mm in size and peripheral in location in at least one ovary
What is the pathophysiology of LH in PCOS
increased LH pulse frequency and amplitude stimulated by GnRH
LH stimulates production of androgens from the theca cells in the ovary leading to hyperandrogenism
What is the pathophysiology of Insulin resistance in PCOS
With PCOS insulin resistance is present regardless of obesity
Insulin has been shown to increase production of androgens in women with PCOS
a. IGF-I receptor binding
b. Decreases production of sex hormone binding globulin produced by the liver. Increases free metabolically active testosterone
What are the health consequences of PCOS
Diabetes Obesity Metabolic syndrome Cardiovascular disease Endometrial Hyperplasia Infertility
What is the cause of cushings syndrome
Excess cortisol from ACTH
Diagnosed by 24 hour urine collection of free cortisol with the level greater than 100 on two determinations
What is ancanthosis nigricans
Raised, velvety, hyper pigmentation of skin, typically seen on the axilla, neck and intertriginous areas
Marker of insulin resistance
Will go away as insulin resistance improves
How can an insulin and glucose be used to determine insulin sensitivity
Glucose/Insulin Ratio
Ratio less than 4.5 in obese adult women
Ratio less than 7 in adolescents
suggested to diagnose insulin resistance
What is the underlying condition in PCOS and how can it be medically treated
Insulin resistance
Metformin
Thiazolidinediones
What is lanugo hair
soft, short hair covering the fetus that is shed in late gestation and during the neonatal period