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