Lec 11 High Risk OB Flashcards
What percentage of twins are identical vs fraternal?
1/3 identical
2/3 frateernal
What kind of twinning is inherited?
double ovum [fraternal] are inherited
single ovum [identical] are due to chance splitting of the ovum
What do the numbers in G2P1001 mean?
G = number of pregnancies P = number of deliveries; 4 digits = TPAL --> term pregnancies, preterm births, abortions/miscarriages, living children
How do you get monozygotic twins?
fertilization of single ovum by single sperm after which zygote divides
usually have 1 placenta with 1 chorion [monochorionic] and 2 amnions [diamnionic]
How do you get monozygotic dichorionic diamnionic twins?
split before day 3
What are risk factors for dizygotic twins?
- multiple ovulations
- increase incidence with increasing maternal age up to 40
- increased parity
How do you get monozygotic monochorionic diamnionic twins?
split days 3-8
How do you get monozygotic monochornionic monoamnionic twins?
days 8-13 split
How do you get conjoined twins?
split after day 13
What are the hazards of twin gestation?
- preterm delivery
- discordant fetal growth
- pregnancy induced hypertension
- anemia
- increased risks of preeclampsia
What are signs of preeclampsia?
- hypertension > 140/90 after 20 wks with previously normal BP
- proteinuria > 300 mg in 24 hr
- symptoms = headache, RUQ pain
What is HELLP syndrome?
preeclampsia PLUS:
- hemolysis
- elevated liver enzymes
- low platelets
What is eclampsia?
new onset grand mal seizures in a woman with preeclampsia
What are risk factors for preeclampsia?
- primagravid
- chronic htn
- diabetes
- chronic renal disease
- auoimmune disease
What causes preeclampsia?
abnromal placental spiral arteries –> causes matenal endothelial dysfunction, vasoconstriction, or hyperreflexia
