17. Multiple pregnancy. Flashcards
what increases the chance of twin pregnancy?
race - africans
maternal predisposition
women the age over 35
clomiphene
gonadotropin
fifth gravida onward.
mean gestational delivery age of twins
36 weeks
what is increased in multiple pregnancy ?
maternal and fetal morbidity and mortality
How does multiple pregnancy occur
fertilisation of single ovum - which splits - identical monozygotic twinning
more common
fertilisation of multiple ovum- dizygotic / non identical/ fraternal/ binovular
in monozygotic twinning arrangement of the fetal membranes will depend on ?
when the embryo divides in the embryogenesis - the earlier the embryo splits to make a twin the separate the membrane and placenta will be
dichorionic , diamniotic in monozygotic twinning the embryo needs to split when ?
within the first 72 hours of fertilisation (prior to morula stage)
diamniotic and monochorionic to occur in monozygosity when does the splitting need to happen?
occurs 4-8 days after development
monochorionic and monoamniotic twins residing in a sac with no septum splitting occurs when ?
if division occurs after 8 days
which division is most likely in incidence for monozygous twins?
diamniotic a thin two layer septum separation will evolve. But monochorionic
which is the least likely in monozygotic twins in terms of the amnion and chorion ?
monochorionic and monoamniotic twins
what are the complications for monochorionic and monoamniotic twins ?
there is no intervening membrane the risk for umbilical cord entanglement is very high - resulting in net mortality of these twins to almost 50 percen
On extremely rare occasions, if division occurs after 2 weeks?
cleavage will be incomplete leading to conjoined twins , most being thoracopagus
dizygotic twin do chorion and amnion morphology ?
separate placentas, separate amnions
determination of what is very important after diagnosing multiple pregnancy ? and why ?
DETERMINATION OF ZYGOSITY
monozygotic higher risk for :
congenital anomalies , weight discordancy , twin twin transfusion syndrome , neurological morbidity premature delivery , umbilical cord abnormality
methods for diagnosing twins ?
US - and two separate foetuses and heart activities made early as 10 weeks of gestation
use of fertility drugs
feeling larger than previous pregnancies
excessive fetal movements
excessive weight gain - suggestive
excessive uterine fundal growth - suggestive
increased subjective symptoms compared to last pregnancy
methods of determining zygosity?
US -
dizygotic - visualisation of thick double aminion chorion septum - twin peak sign or lambda sign
two different placenta which is usually close together
monozygotic :
splitting early the signs above
if septum
quite thin
“T-sign” there is only two amnions and no chorion
and one placenta
or no septum at all present
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twins having opposite sex are almost always dizygotic
If the fetuses are of the same sex and have the same genetic features (dominant blood group), monozygosity is likely
communicating vessels in mono zygotes present but absent in dizygotic
A test skin graft—Acceptance of reciprocal skin graft is almost a certain proof of monozygosity.
investigation of placenta after birth
DNA microbe technique = definite
what is the antepartum management ?
diet - increased calories and protein
and folic acid and iron
US
fetal surveillance
routine use of betamimetics or cerclage operation has got no significant benefit on preterm labour !.
Use of corticosteroids to accelerate fetal lung maturation is given
Antepartum ultrasound management in twin pregnancy?
between 16-22 weeks - patient seen every two weeks for US
fetal growth monitored by US every 4-6 weeks beginning of the 24th gestation week
after 36 weeks
Non stress testing , or biophysical profile
umbilical artery doppler effect
antepartal maternal complications?
anemia - blood volume increases so demand of iron,
increased iron and folate requirement by the two fetuses- megaloblastic anemia
eclampsia and preeclampsia
hydroaminos - usually in second sac
dyspnea ,
orthostatic hypotension due to compression of the vena cava and aorta
compromise of renal function due to compression of the ureters
PROM
placenta abruption
labour complications
complications?
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fetal complications ?
malpresentations very common - usually the first baby is in vertex
umbilical cord prolapse ,
PPH - REAL DANGER
atony due to overextension of uterus
longer time for placenta separate and bigger surface area placenta
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miscarriage esp in monozygotic
vanishing twin in second trim
prematurity
intrauterine growth restrictions and discordant twin growth
congenital anomalies- more in monozygotic
as[hyxia and still birth - more in monozygotic
what is the management during labour ?
if monoamniotic twin then delivery by c section is usually accomplished by 34-36 weeks because of the increased risk of cord entanglement
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Vaginal delivery is allowed when both the twins are/or at least the first twin is with vertex presentation.
to choose the safest route of delivery the presentation of the foetuses must be known
the presenting twin is designated as twin A and the second twin twin B
(most common) vertex-vertex
vaginal or prefer c section
vertex - breech
twin a - vaginal
twin b - vaginal if not c section
breech -vertex (c cessation)
breech - breech ( c section)
because the second twin is more likely to have cord prolapse ,head entrapment, neck injury and asphyxia , placenta abruption - fetal heart monitoring is always necessary
management for delivery of first baby ?
Not to give intravenous ergometrine with the delivery of the first baby.
Liberal episiotomy under local infiltration with 1% lignocaine. (ii) Forceps delivery, if needed, should be done preferably under pudendal block anesthesia.
Clamp the cord at two places and cut in between, to prevent exsanguination of the second baby through communicating vessels in monozygotic twins
At least, 8–10 cm of cord is left behind for administration of any drug or transfusion, if required
conduction of vaginal delivery of second twin?
Following the birth of the first baby, the lie, presentation, size and FHS of the second baby should be ascertained through abdominal and US
A vaginal examination is also to be made not only to confirm the but to note the status of the membranes and to exclude cord prolapse,
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Lie longitudinal:
Step 1: Low rupture of the membranes is done after fixing the presenting part on the brim.
Syntocinon may be added to the infusion bottle to achieve this. Internal examination is once more to be done to exclude cord prolapse.
Step 2: If the uterine contraction is poor, 5 units of oxytocin is added to the infusion bottle.
The interval between deliveries should ideally be less than 30 minutes.
Step 3: If there is still a delay (say 30 minutes)
Vertex: • Low down — Forceps are applied.
• High up — If the first baby is too small and the second one seems bigger, cephalopelvic
disproportion should be ruled out and The possibility of hydrocephalic by ultrasonography. If these are excluded, internal version followed by breech extraction is performed under general anesthesia.
or ventouse
Breech: The delivery should be completed by breech extraction.
Lie transverse:
corrected by external version into a longitudinal lie preferably cephalic.
If the external version fails, internal version under general anesthesia followed by breech extraction
what is twin twin transfusion syndrome ?
EXCLUSIVELY IN MONOZYGOTIC TWINS
one twins circulation perfuses into another - typically atriovenous connections
the arterial blood from the donor twin enters the umbilical arteries and taken by the umbilical venous system belonging to the recipients twin
in twin twin transfusion what does the donor twin deal with?
hypovolemia , hypotension , anemia , oligohydroaminos and growth restriction, absent bladder
in twin twin transfusion what does the recipient twin deal with?
cardiomegaly , ascities , hydros ,hypervolemia , hydroaminos , hyperviscosity , thrombosis , hypertension , polycethmia , edema and congestive heart failure
how is TTS diagnosed ?
ultrasound
treatment for TTS
Treatment- serial amniocentesis, fluid reduction from the recipient twin`s sac and laser photocoagulation of the anastomosis vessels
Septostomy (making a hole in the dividing amniotic membrane)
what is arterial -arterial placental anastomoses
arterial circulation of donor twin enters the arterial circulation os the recipient twin - causing thrombosis
what is retained dead fetus syndrome?
it is not unusual for one twin to die in uteri but it leaves poor outcome of the other twin esp in monochorionic placenta
he surviving twin runs the risk of cerebral palsy, microcephaly, renal cortical necrosis and DIC
due to thromboplastin liberated from the dead twin
if it occurs before 12 weeks of gestation the the dead fetus is reabsorbed
Absence of 1 umbilical artery is very significant because in monozygotic twins because ?
is associated with other congenital anomalies (renal agenesis). Marginal and velamentous umbilical cord insertions
Postnatally twins on average are shorter and lighter than singletons of similar birth weight until?
4 years of age
management of third stage of labour in vaginal delivery ?
risk of postpartum hemorrhage can be minimized by routine administration of 0.2 mg methergine IV or oxytocin 10 IU IM following the delivery of the second baby
blood transfusion given is more than normal blood loss
The patient is to be carefully watched for about 2 hours after delivery.
