Multiple Pregnancy

Definition

Presence of more than one fetus in the uterus

Simultaneous development of two or more fetuses

Incidence

Hellin’s law: “80 to the power of (n − 1)”

Where n is the number of fetuses:• Applies to dizygotic twinnning

4;1000- monozygotic

RFs

Increasing maternal age till about 40yrs, then decline, peak age is 35yrs

Maternal family hx

PARITY-typically above para 2

Types of twin pregnancy

1. Monozygotic twins/identical/ uniovular twins

2. Dizygotic twins/ fraternal/ binovular twins

Features of identical twins

Features of fraternal twins

Outcome of monozygotic pregnancies depends on?

What are the various outcomes?

➢ TIMING OF DIVISION after fertilization

1. Day 1-3: Dichorionic, diamniotic

2. Day 4-8: Monochorionic, Diamniotic

3. Day 9-12: Monochorionic, monoamniotic

4. Day 13 up: conjoint twins (after primitive streak has appeared)

Types of conjoint twins

1. Ventral

2. Lateral

3. Dorsal

Define superfecundation and superfetation

Diagnosis

Hx

Exam

USS

Hx: excessive fetal movement, presence of RFs, maternal family hx

Exam:barrel shaped uterus, large for date, more than two fetal poles, palpation of multiple fetal

Parts , two diff heart sounds at seperate spots with silent area between them

Findings on USS

USS

1. Viability of fetus

2. Chorionicity 6-9wks

3. Twin transfusion

4. Placental localization

5. Amniotic fluid volume

Twin peak sign is for?

Dichorionic gestation

T sign is for?

Monochorionic gestation

Differentials

Weekly antenatal starts from?

32wks

Modes of delivery

VT: ECV or IPV and breech extraction for the second twin

Complications of multifetal gestation

Fetal complications

1. Vanishing twin syndrome

2. Prematurity

Twin to twin transfusion syndrome

1. Occurs in?

2. Causes

3. Types

4. Clinical features of donor and recipient

1. Monochorionic twin

2. Unbalanced placenta vascular anastomoses( ie.blood from one twin goes to another

3. Arterio-arterial, arterio-venous, veno-venous

4. Donor: anemic, oliguric, oligohydramnios, IUGR

5. Recipient: plethoric, polycythemic, bivent hypertrophy, CHF, death

Mgt of TTTS

1. Reductive amniocentesis

2. Septostomy

3. Fetoscope laser occlusion of chorangiopagus

Twin Reversed Arterial Perfusion Sequence

1. Occurs in?

2. Features

3. Who dies first and why?

1. Monochorionic monozygotic/ uniovular

2. Acardiac twin/ recipient/ parasitic twins: no heart, is perfused by donor twin, poorly developed head and upper limbs

3. Donor twin/ pump twin: perfuse the other twin with deoxygenated blood via umbilical artery

4. pump twin, heart failure

Discordant growth in TRAPS

HC: head circumference

AC: abdominal circumference