OB Exam 3 - NL & ABNL Multiples Diagram | Quizlet

Multiples are at greater risk for...

Premature delivery

Low birth weights/FGR

Congenital anomalies

Fetal demise

Cord knotting

Placenta abruption/previa/vasa previa

Preeclampsia/HTN

Bleeding/post-partum hemorrhaging

Dizygotic Twins

Fraternal twins

70% of twins

2 of everything

Sonographic Appearance of Dizygotic Twins

Twin peak sign

Thick membrane

Twin Peak Sign/Lambda Sign

All Dizygotic Twins must be classified as...

Dichorionic diamniotic

Monozygotic Twins

Identical twins

Single ovum that divides

Dichorionic Diamniotic

25% of monozygotic twins

Divides between 0-3 days

10% mortality rate

Monochorionic Diamniotic

75% of monozygotic twins

Divides between 4-7 days

25% mortality rate

Monochorionic Monoamniotic

Divides after 8-13 days

50% mortality rate

High risk of conjoined twins

Monoamniotic twins must be classified as...

Monochorionic and monozygotic

Monoamniotic twins are associated with...

Cord knots

Conjoined twins

Monochorionic twins must be classified as...

Monozygotic

Can be monoamniotic or diamniotic

Sonographic Appearance of Monochorionic Twins

Thin membrane

Monochorionic twins are associated with...

TTTS

TRAP

FGR

Sonographic assessment protocol for twins

Number of sacs & fetal poles

Number & location of placentas

Membrane thickness and movement

Gender of the feti - after 16 weeks

Biometry comparison

Umbilical cord Doppler

Fluid assessment

Presence of anomalies

Assign a letter to each baby - baby A is always closest to the internal os of the cervix

Vanishing Twin

Early twinning with a demise of 1 twin

Demised twin is reabsorbed

Appearing Twin

Only occurs when scanned prior to 6 weeks

10% of dichorionic twins

80% of monochorionic twins

Fetal Papyraceous of Twin

Fetal demise too large to be reabsorbed

Fetus appears flattened due to oligohydramnios

Cord Entanglement

Occurs only in monochorionic monoamniotic twins

50% compromise blood flow - end in fetal demise

Growth Discordance

>20% overall difference between the twins

AC difference of 20mm

BPD difference of 6mm

Femur length difference of 5mm

Causes of Growth Discordance

Idiopathic

Placental issues

Twin to twin transfusion

Tight Membrane

Amnion is wrapped tightly around the smaller twin

Twin to Twin Transfusion Syndrome (TTTS)

Occurs in monochorionic diamniotic twins

AV shunt in placenta pulls blood away from one twin and toward the other

Donor Twin in TTTS

Poor nutrition and oxygen

Anemic

FGR

Oligohydramnios

Recipient Twin in TTTS

Normal to macrosomic

Excess blood in kidneys and heart

CHF

Hydrops

Polyhydramnios

Stage 1 TTTS

Amniotic fluid discrepancy

Stage 2 TTTS

Amniotic fluid discrepancy

Absent bladder in donor twin

Stage 3 TTTS

Amniotic fluid discrepancy

Absent bladder in donor twin

ABNL umbilical artery S/D ratio in donor twin

Ductus venosus flow reversal in recipient twin

Stage 4 TTTS

Amniotic fluid discrepancy

Absent bladder in donor twin

ABNL umbilical artery S/D ratio in donor twin

Ductus venosus flow reversal in recipient twin

Hydrops in recipient twin

Stage 5 TTTS

Death of at least 1 twin

Untreated TTTS

70-80% mortality rate of at least 1 twin

Serial Reduction Amniocentesis

Reduces polyhydramnios

No more than 3L at a time

60% survival of 1 twin

Not effective in severe stages of TTTS

Septostomy

Hole created between twins to equalize pressures

80% survival of 1 twin

60% survival for both twins

Possible complications from septostomy

PROM (premature rupture of membranes)

Premature labor

Infections

Hole enlargement - cord entanglement

Ablation of Placental Anastomotic Vessels

Laser used to coagulate anastomosing placental vessels

75% survival of 1 twin

60% survival of both twins

Possible complications from ablation of placental anastomotic vessels

PROM

Premature labor

Infection

Bleeding at ablation site

Recurrence of TTTS

Stuck Twin Syndrome

Seen in monochorionic diamniotic twins with TTTS

Severe polyhydramnios of 1 twin, and oligohydranmios of the other

Little/no movement of babies

TRAP Sequence

Occurs in monochorionic twins

Artery-to-artery connection

TRAP Twin

No heart

Absent upper body

Reversal of flow in umbilical artery

TRAP Sequence with no treatment

Loss of TRAP twin

50% mortality of normal twin

TRAP Sequence with radiofrequency ablation

95% survival of normal twin

Conjoined Twins

Incomplete division of embryo - division after 13 days

Occurs in monochorionic monoamniotic twins

TERM

Thoracopagus Twins

DEFINITION

Conjoined at thorax

TERM

Omphalopagus Twins

DEFINITION

Conjoined at anterior wall

TERM

Craniopagus Twins

DEFINITION

Conjoined at cranium

TERM

Pygopagus Twins

DEFINITION

Conjoined at buttocks

TERM

Ischiopagus Twins

DEFINITION

Conjoined at ischial region

TERM

Cephalopagus Twins

DEFINITION

Conjoined at back of head

Fused in the upper portion of the body

TERM

Rachipagus Twins

DEFINITION

Conjoined at the vertebral column

TERM

Parapagus Twins

DEFINITION

Conjoined at the abdomen and pelvis