First Principles and Early Pregnancy - Test 1 Flashcards
With regards to the HPG axis, state which hormones act on the various gonadal cell types.
FSH –> Sertoli cells (male) and Granulosa cells (female)
LH –> Leydig (male) and Theca cells (female)
Which neurons in the CNS are responsible for mediating the negative feedback of the HPG axis?
Kiss1 neurons release kisspeptin to upregulate GnRH release from the hypothalamus.
Where does sperm production occur?
Seminiferous tubules
What do Sertoli cells make?
Anti-mullerian hormone (for sex differentiation)
Inhibin (neg. feedback for HPG axis)
Androgen binding protein (ABP) - concentrates testosterone for spermatogenesis
Is GnRH secreted constitutively, or in a pulsatile fasion?
Pulsatile bitch
Name a GnRH analogue that is used to treat prostate cancer. How does it work?
Leuprolide is a GnRH receptor agonist that downregulates LH and FSH secretion
At what cell cycle stage are primary oocytes arrested?
Prophase I
At what cell cycle stage are secondary oocytes arrested? When do oocytes complete meiosis?
Metaphase II. Meiosis is completed after fertilization.
How early in pregnancy can hCG be detected? When does hCG peak?
Can be detected as early as 7-10 days after fertilization. Peaks at the end of the first trimester.
Describe the relative potencies of androgens.
DHT > Testosterone > Androstendione > DHEA
Describe the relative potencies of the estrogens.
E2 (17-beta estradiol) > E1 (estrone) > E3 (estriol)
Describe the relative potencies of the progestens.
Progesterone > 17-OH-progesterone
What is the first, rate-limiting step in sex steroid synthesis?
Cholesterol –> pregnenolone
Which hormone has higher affinity for sex hormone binding globulin: 17-b-estradiol (E2) or testosterone?
Testosterone
Name two selective estrogen receptor modulator (SERM) drugs, their clinical indications, and side-effects.
Tamoxifen - used for breast cancer; side effects are increased thrombosis risk
Raloxifene - treats osteoporosis; no side effects listed
What is the MOA of clomphine, its indications for use, and what are its side effects?
Partial estrogen receptor agonist
Used to induce ovulation and to treat male infertility
No side effects
Name a drug that treats vaginal dryness. What is its MOA?
Ospemifene. Partial estrogen receptor agonist at vaginal tissue.
Which enzyme converts testosterone –> DHT?
Name a drug that blocks this enzyme and its clinical use.
5-alpha-reductase
Finasteride blocks it to treat BPH, male-pattern baldness, and for male-to-female transexuals
At what age does spermatogenesis begin?
Puberty (~13 yo)
Anatomically, where does fertilization occur? What cell stage implants into the uterus?
Fertilization happens in the ampulla of the tube. Blastocyst implants.
When is fetal blood flow initiated?
A week after implantation (implantation happens 7-10 days after fertilization)
Define the following:
1st trimester
2nd trimester
3rd trimester
Preterm
Term
Post-term
1st trimester is 1-13 weeks gestation
2nd trimester is 14-27 weeks gestation
3rd trimester is 28-40 weeks gestation
Preterm is <37 weeks
Term is 37-42 weeks
Post-term is >42 weeks
What is the classic period for teratogenicity?
Between 4-10 weeks gestational age
What teratogen category are most medications in? What does that mean?
Category C. Means that it can’t be ruled out that the drug is not a teratogen but there is no clear evidence that the drug is harmful to fetal development.
What category of teratogenicity is considered to have the highest fetal risk? Name four drugs that fall into this category.
Category X
Vaproate
Coumadin
Methotrexate
Accutane
What are the TORCHeS infections?
T = Toxo
O = Other
- Zika
- Parvovirus
R = Rubella
C = CMV
H = HSV
e nothing
S = Syphilis
Name the noninvasive newborn screening tests and when each can be performed.
1st trimester:
Nuchal translucency US (11-14 weeks)
Cell free DNA screening (after 10 weeks)
2nd trimester:
Serum and nuchal translucency tests (integrated screen) - 15-21 weeks
Anatomic ultrasound (18-22 weeks)
What diseases are increased nuchal translucency associated with?
Trisomies 13, 18, 21, and Turner syndrome
Name the invasive fetal screening tests and when they can be performed.
Chorionic villous sampling (11-14 weeks)
Amniocentesis (after 16 weeks)
Describe the expected relative values expected on a quad screen for Trisomies 18, 21, and neural tube defects.
What is the DDx for 1st trimester bleeding?
Ectopic pregnancy
Threatened or inevitable abortion
Molar pregnancy
Implantation bleeding
Uterine, cervical, or vaginal lesions
Subchorionic or placental hemorrhage
(+ pyelonephritis in real life)
These symptoms are classic for…?
Female of reproductive age presents to ED with pelvic pain and vaginal bleeding. Pregnancy test is positive.
Ectopic pregnancy
What are the treatments for ectopic pregnancy?
Medical (must be hemodynamically stable, can’t have kidney or liver disease, must be reliable for follow-up): methotrexate
Surgical: salpingectomy (if in fallopian tube)
How do you manage incomplete abortion?
Misoprostol (PGE1) or D&C
What are the genetic possibilities or molar pregnancies? What abnormal lab findings might you expect in a patient with a molar pregnancy?
Empty oocyte fertilized by two sperm.
Normal haploid oocyte fertilized by two sperm.
hCG levels are really high in molar pregnancy.
What are the four basic principles of teratogenicity?
- Time-dependent (4-10 weeks gestation)
- There is a specific mechanism that causes the abnormal development
- The teratogen has to have access to the developing tissue
- Teratogenicity is dose-dependent
What four ultrasound findings are suggestive of neural tube defects?
Meningocele/myelomeningocele
Anencephaly
Lemon sign
Banana sign
