multifetal gestation- moulton Flashcards
what is the general pattern as you add kids into multifetal births?
as you get more and more, they get smaller, and born earlier, with a higher chance for having a major handicap
what is a monozygotic twin?
arises from the cleavage of a single fertilized ovum that splits during embryogenesis
what is a dizygotic twin?
arises from the separate fertilization of two eggs with two sperms in the same uterus`
how are dizygotic twins organized in the the uterus?
they have separate amnions, chorions and placentas
what is the result of monozygotic twins that separate from day 0-3?
dichorionic, diamniotic
what is the result of monozygotic twins that separate from day 4-8?
monochorionic, and diamniotic
this is the MOST COMMON PRESENTATION
what is the result of monozygotic twins if they divide from day 9-12?
monochorionic, monoamniotic
most dangerous becasue they are in the same amnion and can get cord tangled ( 50% net mortality)
what is the result of cleavage of monozygotic twins from day 13-15?
conjoined twins
thoracopaus ( joined by thorax) is the most common presentation
what is the frequency of monozygotci twins?
1 in 250
what is more common, monozygotic or dizygotic?
dizygotic
increased frequency with increasing maternal age
what should you suspect if the hCGis higher than normal ?
multiple fetuses in the uterus
what is the most important step in dealing with twins after you determine there are twins?
determine the zygosity
what do yiou see on ultrasound for dizygotic?
peak, or inverted V sign
how must you deliver conjoined twins?
C-section
what is the msot common interplacental vascular anastamosis? 2nd most common?
arterial to arterial
second most common is arterial- venous
what does an uncompensated arterial- venous anastamosis lead to?
twin twin transfusion syndrome
what are the characteristics of TTTS/
donor twin- smaller of the twins, hypotension, hypovolemia
recipient twin- larger, thrombosis, cardiomyopathy
what is the appearance of the smaller twin on ultrasound?
“stuck on” appearance
hwo do you treat TTTS?
serial amniocentesis, or laser photocoagulation
what do arterial-arterial anastamosis lead to?
thrombosis in one of the twins, which leads to ACARDIAC twin, this happens becasue the twin that is getting the deoxygenated blood doesnt get an upper body( this is the recipient twin in arterial-arterial anastamosis)
what are the differnet things that can come from retained fetal parts?
if before 12 weeks= absorbed
if greater than 12 weeks- shrinks and drys up, becomes a fetus papyraceus
after 20 weeks= dead fetus syndrome
what are some complications of multiple gestations in the mother?
hydramnios, anemia, uterine atony ( most common cause of post birth hemorrhage)
when doing serial ultrasounds on twins, what is the diparity you start to get worried about when it comes to difference in twins size?
20% deifference in the size of the twins= worisome
when should monoamniotic twins be delivered?
34-36 weeks, due to increased chance of lethal cord entaglement
if not monoamniotic, when is it recomended to deliver twins?
at 38 weeks
what is twin A? B?
twin A is the presenting baby ( first one that is going to exit the vagina) B is the second twin
whcih twin is at an increased risk for complications?
Twin B
what is the most common presentation of twins?
vertex-vertex
how do you deliver breech- breech, or breech-vertex twins?
C-section, ALWAYS
how must you deliver multiple fetuses above twins?
C section- no matter what, above two babies
what axis is the breech presentation in?
longitudinal
what is most common breech position?
Frank- legs up over head- 65%
complete- cannon ball 25%
incomplete- jackknife -10%- risk of umbilical prolapse more common with this
what is external cephalic version?
moving the fetus from outside to get them in a better position to birth vaginlly, DONT DO THIS if you can’t/ arent going to deliver vaginally, only do this after 36 weeks NOT in labor
when doing external cephalic version, what can you give mom to relax the uterus to make it easier to flip the baby?
terbutalline
if delivering a breech baby vaginally, when can you/should you apply traction to the baby?
after you can visualize the inferior part o the scapula- thei reduces the risk of head entrapment
what forceps are used for an assisted breech delivery?
PIPER
how do most physicians deliver breech babies?
C section
what is the brow presentation?
presenting part of the fetus is between the facial orbits and anterior fontanelle, if a baby has a persistent brow presentation , CAN NOT DELIVER VAGINALLY
what is the face presentation?
full extension of the fetal head and neck with occiput against upper back
which type of face presentations can you deliver vaginally?
mentum anterior, this is how 80 percent of these babies present, if the baby is mentum posterior- CAN NOT DELIVER VAGINALY
what is compound presentation?
when fetal extremity (hand) is found prolapsed alongside the presenting fetal part
