Flashcards in High Risk & Multiple Gestation Deck (98)
Twin gestation account for how many of all live births in the US?
Twins have a __ times greater chance of perinatal death than a singleton.
Clinically, twin pregnancies present with symptoms of...
1. increased MS-AFP
2. earlier and more severe pelvic pressure causing hemorrhoids, constipation, backaches, shortness of breath
3. increased fetal activity
4. increased uterine size
T/F? The baby closer to the cervix is designated as Twin A.
Twins are either monozygotic or dizygotic, depending on...
the number of eggs fertilized at conception.
The term 'zygosity' refers to...
the number of zygotes involved.
The term 'chorionicity' refers to...
the type of placentation in a twin pregnancy.
T/F? The second trimester is the best time to determine chorionicity and amnionicity in multiples.
In the first trimester, what do you look at to determine chorionicity?
The number of gestational sacs, amnions, and yolk sacs.
In the 2nd & 3rd trimester, what do you look at to determine chorionicity?
The genders, the number of placentas, the appearance of the dividing membrane.
If differing genders or two distinct placentas are noted then __chorionic placentation has occured.
If the same gender and one placenta are noted, then what can we determine about the placentation?
It could be anything!! Look at the membranes next to narrow it down.
T/F? The dividing membrane in a di-di gestation is only two layers thick.
FALSE, four layers
T/F? The dividing membrane in a mono-di gestation is only two layers thick.
A cut-off level of greater than __ in septal thickness suggests dichorioncity.
The type of chorionicity in monozygotic twinning is determined by...
how early the twins divided from the single zygote.
Identical twins occur when the embryo splits between __ and __ days post conception.
2 and 14
Identical twinning occurs in about __ pregnancies.
If the embryo splits before day 3, what kind of chorionicity results?
If the embryo splits between days 4 and 7, what kind of chorionicity results?
If the embryo splits between 8 and 13 days, what kind of chorionicity results?
If the embryo splits after 14 days, what kind of chorionicity results?
mono-mono conjoined twins :(
Di-di twins occur when the embryo splits before day...
Mono-di twins occur when the embryo splits between day...
4 and 7.
Mono-mono twins occur when the embryo splits between day...
8 and 13.
Conjoined twins occur when the embryo splits after day...
Mono-di twins have how many placentas?
Di-di twins have how many placentas?
Either two separate placentas or one big fused one.
From the __ weeks, the number of sacs and/or placentas is an accurate method for determining chorionicity.
6th through 10th