Protocol for management of

Multiple pregnancy

Aboubakr Elnashar

Benha university Hospital, Egypt

Sources:

SOGC, 2011

NICE, 2012

Types of twin

pregnancy

1. Dichorionic: (DC) Each baby has a separate

placenta.

2. Monochorionic

diamniotic: (MC DA) Both babies share a placenta but

have separate

amniotic sacs.

3. Monochorionic

monoamniotic: (MC MA)

Both babies share a placenta

and amniotic sac.

Splitting in first 3 d after fertilization: Diamniotic, Dichorionic pregnancy

Splitting between d 3 and 9: Diamniotic, Monochorionic pregnancy

Splitting between d 9 and 12: Monoamniotic, Monochorionic pregnancy

Splitting after the 12th d: Conjoined twins

Types of triplet pregnancy

1. Trichorionic:

Each baby has a separate placenta and amniotic sac.

2. Dichorionic triamniotic:

One baby has a separate placenta and two of the babies

share a placenta. All three babies have separate amniotic

sacs.

3. Dichorionic diamniotic:

One baby has a separate placenta and amniotic sac and

two of the babies share a placenta and amniotic sac.

4. Monochorionic triamniotic:

All three babies share one placenta but each has its own

amniotic sac.

5. Monochorionic diamniotic:

All three babies share one placenta. One baby has a

separate amniotic sac and two babies share one sac.

6. Monochorionic monoamniotic:

All three babies share a placenta and amniotic sac.

A. Antenatal I. Determining g age and chorionicity

II. ANC

III.Fetal complications: screening

IV.Maternal complications: screening

V. PTL: prediction and prevention

VI.Indications for referral to fetal medicine

centre

B. Delivery I. Timing of delivery

II. Mode of delivery

III. Vaginal delivery

IV. CS

I. Determining g age and chorionicity US:

when CRL: 45 mm to 84 mm (11-14 W)

A. Estimate g age

B. Determine chorionicity

C. Screen for Down's syndrome

Use the largest baby to estimate g age

{avoid the risk of estimating it from a baby with

early growth pathology}.

When twin pregnancy is the result of IVF,

accurate determination of gestational age should

be made from the date of ET. (II-1A)

B. Determine chorionicity using

1. Number of placental masses

2. Lambda or T-sign

3. Membrane thickness.

Assign nomenclature to babies

(upper and lower, or left and right) and document

this clearly in the woman's notes to ensure

consistency throughout pregnancy.

After 14 w 0 days,

determine chorionicity

As above plus discordant fetal sex.

If TAS are poor {retroverted uterus or a high BMI}:

TVS to determine chorionicity.

Do not use 3DUS to determine chorionicity.

Dichorionic Diamniotic twin: a triangular projection of chorionic tissue

emanating from fused dichorionic placentas and extending between layers

of the intertwin membrane.

< 20 w Preferably< 14 W

dichorionic twin in the first trimester: a thick intertwin

membrane 16 and 24

Monochorionic Twins: a thin

intertwin membrane

16 and 24

Monochorionic Twins

(20%).

(One placenta)

T sign

II. ANC Multidisciplinary team:

1. Specialist obstetricians

2. Ultrasonographers

3. Foetal medicine Referrals center

1. Information and emotional support

Explain aims and possible outcomes of all

(screening and diagnostic) tests {minimise anxiety}.

2. Diet, lifestyle and nutritional supplements

Same as in routine ANC.

Higher incidence of anaemia

CBC

At 20–24 w {identify who need early

supplementation with iron or folic acid

At 28 w: as in routine ANC

3. Frequent AN visits combined with US

First

CRL measures from 45 mm to 84 mm (11- 14 w)

MC: every 2 to 3 w, starting at 16 w

DC: every 3 to 4 w, starting from the anatomy

scan (18 to 22 weeks) (II-1)

III. Fetal complications

Information about screening

Before and after every screening test.

.

1. Screening for Down's syndrome

2. Screening for structural abnormalities

3. Screening for feto-fetal transfusion syndrome

4. Screening for IUGR

1. Screening for Down's syndrome

Why: {greater likelihood of Down's syndrome in

twin and triplet pregnancies}

When

CRL measures from 45 mm to 84 mm (11-14 W)

How:

Map the fetal positions

Use the combined screening test:

Nuchal translucency

ßHCG,

Pregnancy-associated plasma protein-A

(PAPPA)

calculate the risk of Down's syndrome

A thickened nuchal translucency of 3.3 mm

2. Screening for structural abnormalities

Cardiac abnormalities

between 18 and 22 w (II-2B)

45 minutes for the anomaly scan

3. Monitoring for feto-fetal transfusion

syndrome

Start diagnostic monitoring at 16w.

Repeat monitoring fortnightly until 24 w.

Weekly monitoring if

intertwin membrane infolding or

amniotic fluid discordance

Incidence:

15% of MC

Pathology:

In MC placenta: vascular anastamoses.

Superficial and deep.

1) arterioarterial (AA)

2) arteriovenous (AV), or

3) venovenous (VV).

Blood from a donor

twin is transferred to a

recipient twin:

growth-restricted

discordant donor twin

markedly reduced

AF: "stuck."

Diagnosis

Early 1. Recipient:

Increased nuchal translucency

Abnormal Doppler of DV

2. Folding of intertwin membrane can at 16w.

Late: 1. Recient:

Polyhydramnios

An enlarged fetal bladder

2. Donor:

oligohydramnios

Severe oligohydramnios: amniotic membrane is closely

applied to the fetus, which lies apposed to the uterine wall

(stuck twin).

bladder can be barely visible

.

Recepient:

1. Increased NT

2. Abnormal Doppler of DV

Inter-twin membrane folding

Donor Twin

Severe Oligohydramnios

Recipient Fetus

Polyhydraminos

….Stuck twin

Inter-twin membrane folding

(arrow = dividing membrane)

Polyhydramnios in g sac A

and oligohydramnios in g

sac B (arrow = dividing

membrane)

4. Monitoring for IUGR

Growth curves

As Singleton

30 min for growth scans

Start at 20 w

undertake scans at intervals of less 4w.

Estimate f Wt discordance using two or more

biometric parameters

Growth discordance: either

Difference (20 mm) in AC or

Difference of 20% EFW. (II-2) Consider a 25% or greater difference in size between twins or triplets

as a clinically important indicator of IUGR

AFV:

deepest vertical pocket

oligohydramnios when < 2 cm

polyhydramnios when > 8 cm. (II-2B)

Umbilical artery Doppler

should not be routinely offered in uncomplicated

twin pregnancies. (I-E) Do not use umbilical artery Doppler US to monitor for IUGR or birth weight differences in twin or triplet pregnancies.

Umbilical artery Doppler may be useful in the surveillance of twin gestations when there are complications involving

the placental circulation or fetal hemodynamic physiology. (II-2)

Discordant growth” A 20% difference in f weights or AC

difference of > 20 mm

There is a 2.5 cm difference in the AC measurements for twin A

and twin B, indicating 2nd trimester growth discordancy

IV. Maternal complications

Hypertension

1. Measure BP and test urine for proteinuria

{screen for hypertensive disorders} at each ANV

2. 75 mg of aspirin daily from 12 w until the birth of

the babies if they have one or more of the following

risk factors for hypertension:

first pregnancy

age 40 years or older

pregnancy interval of more than 10 y

BMI of 35 kg/m2 or more at first visit

family history of PET.

V. Preterm birth 1. Prediction

women with twin pregnancies have a higher risk of

PTL if they have had PTL in a previous singleton

pregnancy.

Do not use cervical length (with or without fetal

fibronectin) routinely to predict the risk

2. Prevention

Do not use the following interventions (alone or in

combination) :

bed rest at home or in hospital

IM or vaginal progesterone

cervical cerclage

oral tocolytics.

3. Untargeted corticosteroids

Do not use single or multiple untargeted (routine)

courses of corticosteroids

{no benefit in using untargeted administration of

corticosteroids}.

VI. Indications for referral to a tertiary level fetal

medicine centre

1. MC MA twin pregnancies

2. MC MA triplet pregnancies

3. MC DA triplet pregnancies

4. DC DA triplet pregnancies

5. Pregnancies complicated by any of the

following:

A. discordant fetal growth

B. fetal anomaly

C. discordant fetal death

D. feto-fetal transfusion syndrome.

Mono-

chorionic

Dichorionic Sequels of Death of Co-

twin

15% 3% Fetal Demise

68% 54% Preterm Birth

34% 16% Abnormal Postnatal Cranial

Imaging

26% 2% Neuro-developmental

Impairment of The Co-twin

Single-twin demise

Management depends on

1. Chorionicity

2. gestation age

3. time since death.

1. MC twin

The surviving fetus is at significant risk of

sustaining damage

{sudden, severe, and prolonged hypotension at the

time of the demise or by embolic later}

>34 w: Immediate intervention

32 to 34 W: corticosteroids & delivery after 48H

< 32 w:Conservative management

A. U/S, CTG, BPP

B. if normal: MRI of the fetal brain 2–3 w after

the co-twin death.

C. Counseling should include the long-term

morbidity in this condition

2. DC

Death of one twin is not a strong indication for

intervention to deliver the surviving twin

A. Expectant management up to 37 w

B. If a condition affecting both twins is present

PET, IUGR: Close surveillance and timely

intervention

C. Regular assessment of coagulation status

B. Delivery

I. Timing of delivery

uncomplicated:

1. MAMC

34W

2. Triplet pregnancies elective birth from 35 w 0

days, after a course of antenatal corticosteroid

3. MC DA twin

elective birth from 36 w 0 days, after a course

of antenatal corticosteroids

4. DC twin

elective birth from 37 w 0 days

For women who decline elective birth

weekly appointments

US: weekly

FBP

fetal growth scans: fortnightly

II. The mode of delivery 1. Triplet:

CS

2. MCMA twins:

CS

3. DC twins:

Very low birth weight infant (1500 g):

CS

Prerequisites for vaginal delivery

continuous intrapartum monitoring

appropriate analgesia

an obstetrician experienced in twin delivery

Presentation of the first twin.

A. Vertex-vertex:

Vaginal delivery .

B. 2nd non-vertex:

The optimal mode is unknown with retrospective

reviews providing support for both CS and vaginal

birth

Indications for CS: 1. Non vertex1st twin (23%) {high-risk of cord complication

and thus foetal demise}

2. IUGR in dichorionic twins

3. Twin 2 significantly larger (> 500 gm) than twin 1

4. Antepartum death of 1st twin

5. Placenta praevia

6. Foetal abnormality precluding safe vaginal delivery

7. Chronic TTTS in monochorionic twins

8. Monoamniotic twins

9. Monochorionic twins

Controversial Indications for CS 1. Maternal request

2. Unfavourable cervix at 39 w in nulliparas

3. Death of 2nd twin

4. Non vertex 2nd twin

5. Previous CS.

III. Vaginal delivery Admission:

Inform obstetric consultant

First stage:

Labour conducted as for a singleton continuous

CTG monitoring in active labour (>4cm).

If there is any doubt about the validity of the

recording or difficulty picking up one of the twins:

US for viability

IVF access

blood sent for CBC/G&SAVE.

The anaesthetic registrar

N.I.C.U. should be aware of the admission.

Second stage:

1. Delivery must be attended by

Obstetric Consultant

Neonatal team

Anaesthetic Registrar

Operating department assistant should also be

immediately available.

2. Both fetal hearts should be electronically

monitored continuously

3. Syntocinon infusion should be made ready for

use after the first twin has delivered, to be used at

the discretion of the consultant [20 units added to 500ml NS at 30ml/h – i.e.20 milliunits

/min.]

4. Delivery of the second twin

Perform an abdominal palpation and vaginal

examination immediately after delivery of twin one

Confirm fetal presentation by US

An assistant to compress the uterus in its long

axis between his or her hands, to encourage a

longitudinal lie in the second twin.

Monitor the FHR of twin two continuously

Perform ARM when clinically appropriate

Aim to deliver the second twin within 30 min

Use US to guide vertex into pelvis

THIRD STAGE:

{significant risk of PPH}

syntocinon and methrgin to be given according to

protocol following delivery of the second twin.

A syntocinon infusion of 20 units in 500ml NS

immediately after the birth of the second twin, and

given at a rate of 120ml/h

[i.e.80 milliunits/minute] for 2-3 h.

IV. Cesarean Delivery 1.Position:

Left lateral tilt {deflect uterine wt off the aorta

Hypotension commonly develops in women

carrying twins when they are placed supine}.

2. The uterine incision:

A. large enough to allow atraumatic delivery of

both fetuses.

B. Vertical in the lower uterine segment.

-fetus is transverse with its back down, and the

arms are inadvertently delivered first,

3. If 2nd twin is breech and delivery of the head is

obstructed

Piper forceps can be used just as for a vag delivery

4. CS of 2nd twin

Attempts to deliver 2nd twin vaginally after delivery

of 1st twin are not only unwise but also impossible

1. Second fetus is much larger than the first and is

breech or transverse

2. Cervix promptly contracts and thickens after

delivery of the first twin and does not dilate

subsequently

3. Non-reassuring FHR pattern develops.

Thank you