twin pregnancy

1. SINGLE FOETAL DEMISE IN TWIN PREGNANCY
DR OKECHUKWU UGWU
REF UNIT

2. OUTLINE• Introduction
• Epidemiology
• Aetiology
• Complication
• Management
• conclusion

3. INTRODUCTION-1
• Single intrauterine fetal death rate in multiple pregnancy is
significantly higher than that in singleton.
• The risk increases with the number of fetuses.

4. INTRODUCTION-2
• loss of a twin during the first trimester is not an uncommon event - vanishing twin
• Opinion is divided as to the risk of developmental defects when there is fetal
demise in the first trimester. Some data are suggestive of a growth anomaly, where
as others exclude such possibility.
• Most studies suggest no association with adverse perinatal outcome for the
surviving twin
• IUFD in the 2nd and 3rd trimester is less common and is more likely to be
associated with complications for the surviving co-twin
• vascular complications - 2nd
• Damage CNS characteristic of 3rd trimester

5. EPIDEMIOLOGY-1
• single foetal demise complicates 2.5% to 5.0 % as compared to 0.3%
to 0.6% in singletons and 4.3% triplet pregnancy
• 3–4-fold greater in MC than DC twin pregnancies
• regardless of the chorionicity, none of these complications occurs
following single foetal demise in the first trimester.

6. EPIDEMIOLOGY -2
• > 24 weeks ; 1.1% of dichorionic twins compared to 3.6% of monochorionic
twins.
• On the other hand, this risk is higher before 24 weeks of gestation and its
prevalence is 12.2% for monochorionic pregnancy and 1.8% for dichorionic
pregnancy.
• When single IUFD occurs in a Monochorionic pregnancy, it is associated
with a worse prognosis, including up to 20% incidence of significant
neurologic morbidity for the surviving co-twin

7. Aetiology
may be spontaneous or iatrogenic
• Twin-twin transfusion syndrome
• congenital anomalies
• placental insufficiency
• abnormal cord insertion – more in monoamniotic
• Intrauterine infection
• Maternal medical conditions
• intrauterine growth restriction. –usu in DCDA

8. Aetiology- 2
• placental abruption
• blunt abdominal injury
• umbilical vein thrombosis
• chorioamnionitis
• Twin reversed arterial perfusion (TRAP)
• Discordant growth
• Foetal reduction

9. Vanishing twin
• Term that has been used to describe the spontaneous loss of a twin
during the first trimester.
• Around 23 per cent of twin pregnancies diagnosed by ultrasound at
six-weeks gestation will be singleton pregnancies by 12 weeks.
• Bleeding or mild cramping may be noticed, but there are no longer
term implications for the pregnancy.
• Grief for the lost twin may be significant especially in IVF pregnancies

10. Discordant Growth
• Spontaneous single fetal loss in DCDA twins is usually a consequence
of growth restriction- frequently unrecognised.
• The risk of fetal death increases with the degree of growth
discordance, particularly when discordance exceeds 30 per cent.
• [larger twin EFW – smaller twin EFW]/larger twin EFW) x 100.

11. Maternal medical conditions
• Pre-eclampsia may result in the loss of one twin only – indeed, loss of
the twin is often associated with a short-term improvement in the
condition.
Selective fetal growth restriction, particularly of the Gratacos type 2
and 3 variants, accounts for significant numbers of fetal deaths in
MCDA twins.

12. Fetal reduction/ congenital anomalies
Fetal reduction
• May be a consequence of either
selective or multifetal pregnancy
reduction.
• The former is performed for a fetal
abnormality.
• The latter may be performed either
because it is deemed medically
unsafe to proceed with a twin
pregnancy
Fetal congenital anomalies
• Much more frequent in MC
twins than either DC twins or
singletons esp cardiac and
neurological anomalies
• Account for a large proportion
of MCDA single twin deaths.
• Most MC twins, although
monozygotic, are discordant for
fetal abnormalities.

13. Monochorionic Diamniotic Twins
• TTT accounts for at least 50 per cent of all single MCDA twin deaths.
• Even with extensive and careful surveillance, the risk of sudden fetal
death in the third trimester in these pregnancies is 1.2 per cent to six
per cent.
• If the laser treatment has been successful; no risk of subsequent
injury to the survivor, but there may be concerns about a pre-existing
insult to the foetus.

14. Monochorionic mono-amniotic twins
• Cord entanglement in MCMA twins accounts for more than 50 per
cent of all losses and may involve one or both twins.
• Fetal abnormalities, particularly cardiac and neurological, complicate
approximately 25 per cent of all MCMA twins.
• The abnormalities are frequently lethal, but the twins are usually
discordant for the abnormality.

15. Figure 1

16. Umbilical vein thrombosis
• Rare but life-threatening event
• predisposing factors; excessive twisting, very long or very short cord,
presence of a true knot, marginal or velamentous placental insertion
• result in vascular ectasia, blood stasis and subsequently thrombosis,
reduced blood flow leading to fetal hypoxia, and intrauterine fetal
death

17. Complications following death of a co-twin
The severity of complications following death of a twin is dependent on
the chorionicity, gestational age and length of time from death to
delivery of surviving twin
• Death of the co-twin
• Neurological sequelae
• Preterm delivery
• Coagulopathy

18. Coagulopathy
• Maternal coagulopathy- the most feared complication following twin
demise
• appears to be uncommon .
• Occurs in about 3–5 weeks following fetal demise.
• Therefore, an initial maternal clotting profile with reassessment in 2–
3 weeks is recommended.
• Monitoring of maternal coagulation factors is not necessary when fetal
loss occurs prior to 13 weeks of gestation

19. Death of the co-twin
• The risk of co-twin death following death of a twin after 20 weeks
gestation is 12 per cent for MC twins and 4 per cent for DC twins.
• 2nd and 3rd trimester

20. Neurological sequelae
• Chorionicity is the prime determinant of outcome when one twin
dies.
• 3rd trimester
• Thromboplastin theory
• Ischaemic theory

21. PRETERM DELIVERY
• It is difficult to determine the average time between fetal death and the
onset of labour as the timing of fetal death is rarely known with any
precision.
• Labour often occurs spontaneously two to three weeks after the
recognition of a fetal death, but may occur almost immediately —
such as following a placental abruption – or may be delayed for many
months.
• before 34 weeks is higher for MC twins than for DC twins: 68 per cent
vs 57 per cent

22. Management
• Management is hampered from the lack of guidelines
• Single fetal death in a monochorionic pregnancy should be referred
and assessed in a fetal medicine centre, with multidisciplinary
expertise to manage these cases.
Obstetricians
Neonatologist
Haematologist
Psychologist
Midwife

23. Management-1
• Management decisions should be based on the cause of death if known
and the risk to the surviving foetus.
• For instance if death of one twin is due to congenital anomaly , its
death should not affect the surviving twin.
• Maternal status should also be considered eg. DKA, severe PE with
abruption

24. Antepartum
• Frequent ante natal visit as it is a high risk pregnancy
• Serial ultrasound+ assessment of amniotic fluid volume
• BPP if up to 32 weeks
• Doppler velocimetry
• NST
• Coagulation profile
• Fibrinogen and fibrinogen degradation product
• Steroid administration for lung maturation
• Magnesium sulphate for neuroprotection.

25. Management -2
Dichorionic Diamniotic twins
• Delivery should be delayed until at least 34 weeks gestation
• provided there is no obvious continuing pathology that may cause demise
of the surviving co-twin.
• Careful monitoring with serial ultrasound assessments of growth and
Doppler blood flow studies as well as
• regular NST should be undertaken.

26. Management
• Monochorionic Twin Pregnancy
• Chorionicity should be determined at the time the twin pregnancy is
detected by ultrasound based upon the number of placental masses, the
appearance of the membrane attachment to the placenta and the
membrane thickness. This scan is best performed before 14 weeks of
gestation.

27. Monochorionic Twin Pregnancy contd
• Fetal ultrasound assessment should take place every 2 weeks in
uncomplicated monochorionic pregnancies from 16+0 weeks onwards
until delivery
• At each scan from 20 weeks of gestation (at 2-weekly intervals)
onwards, calculate EFW discordance using two or more biometric
parameters
• Liquor volumes as DVP should be measured and recorded (to
differentiate from TTTS).

28. MONOCHORIONIC TWIN PREGNANCY
contd
• When fetal death has been identified in MC twin pair, the neurological injury has already
been inflicted.
• If the foetus has survived that insult, delivery should be delayed as long as possible.
• This will give the greatest chance of detecting any intracranial pathology.
• Weekly ultrasounds should be performed
• Fetal MRI of the brain may be performed 3-4 weeks after co-twin demise to detect
neurological morbidity if this information would be of value in planning management.
• Fetal anaemia may be assessed by measurement of the fetal MCA PSV using Doppler
ultrasonography.
• The use of a ’rescue‘ fetal blood transfusion has been attempted in several centres, with
varying results

29. Monochorionic monoamniotic twins
• The majority of deaths in MCMA twins involve the death of both twins.
• Occasionally a single MCMA twin may survive the death of its co-twin.
• The rarity of this circumstance makes it difficult to offer specific advice,
• but it must be noted that the rate of neurological sequelae in these
survivors is extremely high.
• It may be appropriate, if the death occurred at a very preterm gestation, to
delay delivery to allow administration of steroids and magnesium sulphate.
• Delivery by 28 weeks gestation would be reasonable in these
circumstances, although it may be too early at that stage to detect
intracranial pathology.

30. CS vs Vaginal delivery
• If the live twin is leading and is in a cephalic presentation, vaginal
delivery may be considered.
• If the live twin is malpresenting or is growth restricted, or if the dead
twin is leading, caesarean section is preferred.
• Many parents prefer caesarean section regardless of these
considerations.

31. Postpartum
• Following delivery, the placenta should be sent for histopathology
• The dead foetus should be sent for postmortem
• The newborn have to be followed through its neonatal period.

32. CONCLUSION
• The sequelae of a single fetal death in a twin pregnancy depend on the
gestational age and chorionicity.
• Death in the late second or third trimester is associated with significant
morbidity and mortality in the surviving twin.
• Therefore, all twin pregnancies with one dead foetus should be managed in
tertiary referral centres with sufficient neonatal support.
• A management plan should be individualized.
• Intensive fetal surveillance is required and the determination of
chorionicity should be done early in the pregnancy.
• Proper care and management can salvage a good number of babies.

33. References
• Babah O A, Olamijulo A, Ayanbode O S, Sanusi M M. Conservative
management of single fetal death in twin pregnancy at a tertiary
health institution in southern Nigeria: a case report. (IOSR-JDMS), Vol
13, Issue 3 Ver. IV. (Mar. 2014), PP 79-83
• Facchinetti F., Dekker G., Baronciani D., Saade G. (2010) Stillbirth, 45-
48. Informa Healthcare; 1 edition.
• Pharoah P.O., Glinianaia S.V., Rankin J. (2009) Congenital anomalies in
multiple births after loss of a conceptus. Hum. Reprod. 24(3): 726-31.