TWIN WITH DISCORDANT GROWTH

Dr. KY Leung MBBS, MD, FRCOG, FHKAM (O&G), Dip Epid & Appl Stat

COS, Dept of O&G, Queen Elizabeth Hospital

Ambassador, ISUOG

Chairman, Education Committee, AFSUMB

Director, HK Branch, Ian Donald School of Medical Ultrasound

5th OGSHK ASM 2016

DISCORDANT IN SIZE

DISCORDANCE & CHORIONICITY

Dichorionic Monochorionic

Placental AV +/-

compensatory

anastomoses

- TTTS

- Discordance

Unequal placenta

sharing

IUGR IUGR

Anastomoses +

unequal sharing

Further impair growth

of donor twin or mask

the growth of recipient

J perinatol 1998, Ultrasound OG 2000, Fetal Diagn Ther 2001

PLACENTA DISCORDANCE VS INTERTWIN ANASTOMOSES

Large

intertwin

anastomoses

Small

intertwin

anastmoses

Large placenta

discordance

sIUGR

Unstable

Rare

Small placenta

discordance

TTTS Benign

PD 2012

SIGNIFICANCE

• 10–15% of MC twin

• A high risk of IUD and neurological deficits.

• Natural history different from singleton and DC

twin because of placenta anastomoses with variable

direction and flow of blood flow and hence effects on

IUGR

UOG 2007

RISKS OF IUD OF ONE MC TWIN

• At least 25% risk of death or 10-15% risk of neurologic damage

to the co-twin because of ischemic or embolisation injury after

demise of a twin

• Evidence for brain injury includes ventriculomegaly,

porencephaly, cerebral atrophy, cystic encephalomalacia and

microcephaly

NEURO-DEVELOPMENTAL OUTCOMES

• Compared to the larger twin of a discordant pair, the smaller

twin performed significantly worse in cognition and also in

language and motor skills.

• Prematurity < 33 week had a far greater impact on cognitive

outcomes

Eur J Paed

MZ TWIN

• Birthweight has an impact on growth and pubertal

maturation.

• The already decreased height in some low birthweight infants

may be further impacted by an early start and fast

progression of puberty. Hence further decreased near final

height.

J Paed 2016

Monochorionic :

- Absence of lambda sign

- Thin dividing membranes

- Single placenta

- Concordant sex

Dichorionic :

- Lamda sign

- Thick dividing membranes

- Two placentae

- Discordant sex

LATE PRESENTATION

Lack of twin peak sign does not mean MC twin,

count layer, but motion artifact

GROWTH PATTERN OF SINGLETON, TWIN, TRIPLET

PREDICTORS OF GROWTH DISCORDANT

• Intertwin CRL discordance ≥10% ass with Birthweight

discordance (OR 2.8)

• Velamentous insertion of cord

JMFNEM 2015, Placenta 2012

DEFINITION

• Not universal established

• EFW below the 10th percentile in one twin.

• Intertwin discordance:(A–B) ×100/A, where A is the EFW of larger

twin and B is smaller twin.

• Discordance > 25% is commonly associated

• The clinical significance of both MC twins with EFW < 10th

percentile, but without intertwin discordance, or those with

intertwin discordance but a smaller fetus > 10th percentile

remains to be established.

(PD 2012)

TTTS VS IUGR

TTTS IUGR

Polyhydramnios Yes no

Superficial

anastomoses

11.8% 72.3%

Quintero RA. AJOG 2001;185(3):689-96

CLASSIFICATIONS

• Type I: positive end-diastolic flow in the umbilical

artery

• Type II: AREDF constantly observed during all the

examination

• Type III (iAREDF): clear observation of AREDF

alternating over a short period of positive diastolic

flow, in the absence of fetal and maternal breathing

Gratacos et al. (2007)

INTERMITTENT A/REDF

• a cyclical pattern

• a sign unique to MC twins resulting from the presence of

transmitted waveforms from the larger into the smaller twin’s

cord due to the existence of placental large AA anastomoses.

• from very early in pregnancy and they normally remain

unchanged until delivery

AmJOG 1994

TYPE III

• Unexpected IUFD of the smaller twin occurred in

15.4% of cases, which was associated with the death

of the co-twin in one-third of cases, leading to IUD

of the larger fetus in 6.2% of cases.

• The rate of neonatal brain injury in the larger twin

was 19.7%, and most cases of brain injury occurred

in cases with double twin survivors (10 of 12 cases).

Gratacos et al. (2007)

HYPERTROPHIC CARDIOMYOPATHY-LIKE

• Creation of a hyperdynamic circulation in the larger twin,

similar to what is found in monochorionics with an acardiac

fetus or large fetal tumors, and it is reflected in the relatively

common prevalence of hypertrophic cardiomyopathy-like

(HCL) changes

(Mu˜noz-Abellana et al., 2007).

TWIN 2, AEDF OF UA

TWIN II WITH AEDF AT 17 WK

Velamentous cord insertion

TWIN WITH INTERMITTENT TO PERSISTENT AEDF

AEDF

SIGNS OF SEVERE HYPOXIA

• Before 28 weeks, absent or reversed atrial flow in

the ductus venosus;

• After 28 weeks, persistent reversed end-diastolic

flow in the umbilical artery, ductus venosus PI

persistently > 2SD, and/or persistently abnormal

fetal heart rate traces and biophysical profile.

Normal Type I

(n=39)

Type II

(n=30)

Type III

(n=65)

GA at Dx 23 wk 20wk 22wk

GA at del 35.5

wk

35.4 wk 30.7wk 31.6wk

BW_larger 2439g 2385g 1468g 1713g

BW_smaller 2187g 1688g 787g 1017g

Discordant 10% 29% 38% 36%

IU deteriorate 0% 90% 10.8%

Unexpected

IUD_larger

2.6% 0% 6.2%

IUD_smaller 2.6% 0% 15.4%

IVH_larger 0% 3.3% 3.3%

IVH_smaller 0% 14.3% 6.0%

Brain dam_L 0% 2.3% 19.7%

Brain dam_S 0% 14.3% 2.0%

UOG 2007

OUTCOMES

Delivery Brain damage

Type I 36 wk 0%

Type II 30 wk 13,6%

Type

III

32 wk 19.7% in the larger twin

UOG 2011

UNIVARIATE ANALYSIS Death (%) OR P

UA Doppler Type I 3%

UA Doppler Type II 49% 28.9 <0.001

UA Doppler Type III 20% 7.5

Isolated polyhydramnios 40% 1.7 0.314

Isolated oligohydramnios 46% 2.7 0.034

Isolated stuck twin 83% 6.2 <0.001

Severe IUGR 38% 3.8 0.019

>=45% discordant in

EFBW

52% 3.5 0.008 UOG 2011

MULTIPLE LOGISTIC REGRESSION

OR P

UA Type II 29.4 0.003

UA Type III 5.6 0.186

Isolated stuck twin 14.5 0.006

Severe IUGR 3.3 0.084

UOG 2011

To prevent acute fetofetal hemorrhage subsequent to IUD

of a sIUGR fetus, umbilical cord occlusion for selective

feticide can be considered viable options for Type II

pregnancies with severe isolated oligohydramnios at early

gestation.

STUCK TWIN

MANAGEMENT OF TWIN WITH ONE IUGR

• Gestation age

• Serial growth

• Fetal well-being

• MC or DC twin

MANAGEMENT OPTIONS OF MC TWIN SIUGR

• Deliver or monitor?

• If severe, impending IUD:

• Selective feticide by umbilical- cord occlusion

or bipolar coagulation (80% success): <24 wk

• Selective photocoagulation of communicating

vessels

Monitoring Delivery

Type I Q1-2 wk Deliver at 34-35 wk

Type II Q1 wk

Include DV PI,

BPP

Expectant: usually deliver

before 32 wk for fetal

deterioration

Option of cord occlusion or

placental laser coagulation

Type

III

Similar to type II,

But the smaller

fetus will seldom

present

signs of

deterioration in

venous Doppler

Deliver between 32-34 wk

or earlier if abnormal

venous Doppler or BPP

PD 2012

SIGNIFICANCE OF ABSENT END-DIASTOLIC FLOW OF UMBILICAL ARTERY IN MC

TWIN • Poorly understood.

• Period of AED most prolonged in rescue transfusion group

(median 8 wk)

• AED not necessarily indicate impending fetal death in the

absence of TTTS and other abnormal fetal monitoring.

Denbow ML. AmJOG 2000;182(2):417-26

INTERVENTION

• It is, and will probably remain, very difficult to

establish criteria for fetal therapy in sIUGR

pregnancies.

• (1) the risks of IUD and or brain injury,

• (2) parents’ wishes and

• (3) technical considerations.

PD 2012

CORD OCCLUSION VS PLACENTA LASER COAGULATION

• Cord occlusion is a straightforward treatment, preventing

exsanguination of the healthy fetus into the dead co-twin. The

chances of survival for the larger fetus range from 80 to 85%.

• If selective feticide is not an acceptable alternative for parents, or

in countries where it is not a legal option (Ishii et al., 2009; Rossi

et al., 2009), laser coagulation of placental anastomoses may be

offered. PD 2012

• But laser may not be feasible in cases where an anterior placenta

is combined with large AA vessels and placental cord insertions,

which are close to each other (UOG 2008).

LASER COAGULATION

• Technical feasible in 88.9% (16/18) of cases

• 12.5% (2/16) a second procedure was required

• Mean gest at delivery was 31.0 wk in the expectant Mx group and 32.6 wk in the laser group.

• Perinatal survival was 85.5% vs 63.9% (P = 0.02).

• IUD of smaller twin in 19.4% vs 66.7% (P = 0.001)

• Death of cotwin in 50% vs 0% (P = 0.02)

• PVL in the larger fetus was 14.3% vs 5.9% (P = 0.63)

UOG 2008

BIPOLAR COAGULATION FOR MCDA TWIN WITH SIUGR

RADIOFREQUENCY ABLATION

• 35 monochorionic pregnancies

• LA, technically successful in all cases.

• The live born rate was 88.6%.

• One (2.9%) woman miscarried within 2 weeks

• Two (5.7%) babies were stillborn.

• Median gest at delivery was 36 wks (24-41)

• No maternal complications.

• Median gest at procedure was 17 wks (12-27)

• Two (5.7%) cases of abnormal brain imaging.

BJOG 2010

RFA VS BPC

Retrospective RFA

(n=20)

BPC

(n=40)

P

Amnioinfusion 10% 75% 0.01

Amnioreduction 5% 40% 0.004

Survival 87.5% 88% 0.94

Median gest@del 36 39 0.59

Preterm <32wk 20% 27.5% 0.52

PPROM 5% 22.5% 0.09

UOG 2010

LATE ONSET SIUGR

• Diagnosed after 26 wk

• Intertwin fetal weight reached on average 30%

• mean gestational age at delivery was 35 weeks.

• UA Doppler was normal in all cases

• IUFD (8%)

• Twin anemia-polycytemia sequence, was 38%.

• Relatively low larger to smaller placental ratio of 1.59, as

compared with 2.55 in early onset IUGR

• A few small, mostly unidirectional, anastomoses.

• MCA-PSV

Lewi et al., AmJOG 2008

Cerebral redistribution

A SPECIALISED TWIN CLINIC IN QEH

Managed by MFM team

Check chorionicity + DS screening at 12 wk

Combined AN +USG/Doppler (every 2-3 wk)

Standardised protocol

Look for TTTS, IUGR, short cervix, anomaly

Maternal: PET

QEH DATA: JUL 2010 TO DEC 2014

• Of 635 twins, 160 (25.2%) were MC.

• TOP: 2.0%

• Miscarriage: 6.6%

• Stillbirth: 0.7%

• NND (all < 30 weeks): 2.6%

• At least one survival (ALOS): 88.8%

• Without any complications, ALOS rate was

100% after 24 weeks and no IUD after 34 weeks.

SIUGR VS TTTS

• sIUGR was more common (30.9% vs 13.2%)

• Diagnosed at a greater gestation (24.6 vs 20.2 weeks)

• Delivered at a greater gestation (34.0 vs 29.3 weeks)

• Lower preterm delivery < 32 weeks (13.3% vs 45.0%)

• A higher ALOS rate (97.9% vs 70.0%)

•

• Of 47 sIUGR, 8.9% had persistent and 8.9% intermittent AEDF.

• Bipolar coagulation of cord in three cases < 24 weeks: success

THANK YOU