Multiple gestation

Question 1

Definition of multiple gestation?

Answer 1

> 1 fetus in uterus

Question 2

Monozygotic twins?

Answer 2

Identical twins
One fertilized ovum 
Ovum splits at different stages :
>2 days - dichorionic, diamniotic
3-7 days - monochorionic, diamniotic
7-14 days - monochorionic, monoamniotic 
14+ days - conjoined twins

Question 3

Dizygotic twins?

Answer 3

Non-identical twins
Two separate ovum, independant fertilization
Dichorionic, Diamniotic

Question 4

Risk factors of multiple pregnancy?

Answer 4

Race - more common in west African 
Advanced maternal age 
previous multiple pregnancy 
IVF
Ovulation stimulation

Question 5

Diagnosis of multiple pregnancy?

Answer 5

Symptoms - hyperemesis gravidarum, Weight gain, very large uterus very early, increased fetal movement
US - check for chorionicity -
monochorionic - one placenta, twin peak sign negative
Dichorionic - 2 placentas, lambda sign (twin peak sign) seen. (suggests twin membrane)

Auscultation - 2 fetal heart beats heard. Arnoux sign - superimposition of two fetus - sounds like a gallop rhythm.

Question 6

complications of multiple gestation?

Answer 6

Maternal - hyperemesis gravidarum, gestational diabetes, spontaneous abortion, placenta previa and abruption, preterm labour, hypertension

Fetal - Preterm labour, IUGR, fetal demise, TTTS, malpresentation

Question 7

TTTS.
What is it
symptoms
treatment

Answer 7

Twin Twin Transfusion syndrome - complication of monochorionic twins.
Donor bleeds into the recipient via placental anastomosis.

Donor twin - anemia, IUGR, oligohydramnios
Recipient twin - polycythemia, larger size, Polyhydramnios, increased amniotic pressure.

Treatment- septostomy, reductive amniocentesis, selective vessel laser ablasion

Question 8

What is TRAP

Answer 8

Twin Reversal Arterial Perfusion.
One twin has underdeveloped heart (acardiac twin)
The other twin maintains adequate perfusion through an anastomosis (pump twin)
Results in cardiac immaturity of the pump twin.

Treatment is cord ligation of the acardiac twin.

Question 9

What is discordant growth ?

Answer 9

A greater than 25% weight difference in weight between the twins.
Common in monochorionic twins, especially in TTTS.

Question 10

Method of delivery in multiple gestation?

Answer 10

If the presenting twin is in vertex position, then vaginal delivery.
If in breech position - C-Section, as risk of twin interlocking syndrome.