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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