Pregnancy Flashcards
Risk of down syndrome by age at Delivery
Down at delivery: 35=1:350, 40=1:100, 45=1:30, 50=1:10
Quad screen testing
T21 (75%):
HCG/Inhibin ↑
uE3/MSAFP ↓
T18 (65%): HCG/uE3/MSAFP ↓
Inhibin N/A
ONTD (85%): ↑ MSAFP
Quad screen does not screen for T13
VTE risk in pregnancy
5-20/10,000 woman years
Molar pregnancy
What enzyme does fetus lack?
3 B OH dehydrogenase
What enzymes does placenta lack?
17a hydroxylase
17, 20 lyase
16a hydroxylase
Three levels of sexual differentiation
o 1- Chromosomal sex: XY, XX, XXY (Klinefelter’s), X0 (Turner’s), XXY
o 2- Gonadal sex: ovary/testes/gonad
o 3- Phenotypic sex: androgens/estrogens
Male development
+SRY SOX9 promotes Sertoli cells, desert hedghehog promotes leydig cells differentiation, T prodn drives male development, DHT: penile length, prostate
Female development
driven by absence of -AMH, also WNT4, RSPO1 B-catenin, HOX genes*
o DES alters HOX gene expression, is mechanism of T-shaped uterus, vaginal adenosis in affected females
HOX genes
- HOXA9: fallopian tubes
- HOXA10: uterus
- HOXA11: Uterus and cervix
- HOXA13: vagina
Virilized female infant
o CAH: 21-alpha hydroxylase, 11-beta hydroxylase (both have high DHEA, androstenedione), 3-beta HSD (mildly virilized, elevated DHEA)
o Maternal androgen prodn
Luteoma (30% women virilized, of virilized moms 80% have virilized fetus)
Sertoli-Leydig tumor (highest risk virilization)
Placental aromatase deficiency (progressive virilzation of mother then baby)
Drugs
When is uterine and vaginal development complete?
16 weeks
When does T production start
8 weeks
8-9 weeks regression of Mullerian ducts
when is male external genitalia complete?
9-14 weeks prostate and external genitalia developed under T and DHT influence
CAH and female genitalia
female external genital development not done until 20 weeks
elevated androgen levels between 10-12 weeks lead to clitoromegaly, labial fusion, and partial closure of the urethra
Dose of folic acid with history of NTD
4 mg
Neonatal treatment of CAH
adrenal crisis is an emergency
hypotension, hyponatremia, hyperkalemia, hypoglycemia, n/v, weight loss, anorexia
Treatment: fluids (0.9%tes, NS 10-20 mL/kg)
electrolytes (correct electrolytes with long term NaCL)
Corticosteroids and mineralocorticoids
P450 Oxidoreductase deficiency
AR caused by missense mutation
affects all P450 enzymes with variable phenotype
Antley Bixler syndrome
craniosynostosis, midface hypoplasia, choanal atresia or stenosis, radiohumeral or radioulnar syntostosis, femoral bowing and fractures, and joint contractures
type of P450 oxidoreductase deficiency
Hormone levels with P450 oxidoreductase deficiency
Basal/stimulated:
17 OHP: high, exaggerated
DHEA/S: low, low
Androstenedione: low, low
Cortisol: low, normal
luteoma
hyperplastic masses of luteinized cells
average 6-10 cm, 1/2 are bilagteral
1/3 have maternal hirsutism/virilization
80% of infants with virilized mothers are also virilized
Regression after delivery, but maternal virilization may not regress
Theca lutein cysts
type of functional cyst
10-15 cm
usually bilateral
regression post deliver
common in women with GTD, molar pregnancies, multiple gestation
mass effect, pain
fetus is NOT virilized
Aromatase deficiency
fetal androgens are not converted to estrogens in the placenta causing low maternal estrogen
Androgen insensitivity syndrome
X linked
Defective T receptor
Testes will develop normally but do not descend (found in inguinal canal)
without T response you get regression of wolffian ducts (internal male genitalia), but also AMH is present so you get regression of mullerian ducts
